Document:

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                                                                    Exhibit 4.30
                                 LOAN AGREEMENT

         THIS AGREEMENT made on July 23, 2000, by and among NORTHERN TRUST BANK
OF FLORIDA, N.A. ("Lender"), SUN HYDRAULICS CORPORATION, a Florida corporation
("Borrower"), and SUN HYDRAULIK HOLDINGS LIMITED, a __________________, SUN
HYDRAULICS LIMITED, a corporation organized and existing under the laws of the
United Kingdom, and SUN HYDRAULIK GMBH, a corporation organized and existing
under the laws of Germany (collectively referred to herein as "Guarantors").

                              W I T N E S S E T H :

         WHEREAS, Borrower has requested Lender to make available to Borrower a
revolving line of credit loan in the maximum principal amount of $7,500,000.00
("Loan"), which loan will be evidenced by a renewal master note of even date
herewith in the principal amount of $7,500,000.00 ("Note"), and

         WHEREAS, the Note will renew, restate, amend and replace in its
entirety, that certain renewal master note dated July 23, 1999, in the principal
amount of $5,000,000.00, and

         WHEREAS, Lender is willing to make the Loan on the conditions herein
and in other Loan Documents.

         NOW, THEREFORE, in consideration of the premises and of the covenants
and agreements herein contained and the agreement by Lender to make the Loan,
the parties hereto agree as follows:

         1. LOAN TO BORROWER; EXECUTION OF LOAN DOCUMENTS. Lender agrees, in
accordance with the terms of this Agreement, to make the Loan to Borrower.
Concurrently herewith, Borrower has executed the Note, an amendment to that
certain Loan Agreement dated July 23, 1999 (the "First Amendment to Loan
Agreement"), an amendment to that certain Security Agreement dated July 23, 1999
(the "First Amendment to Security Agreement"), and other documents related to
the Loan. Guarantors have each executed separate guaranties of the Loan
("Guaranties"). The Note, First Amendment to Loan Agreement, First Amendment to
Security Agreement, Guaranties, this Agreement and other documents are
collectively referred to herein as the "Loan Documents."

         2. COSTS AND EXPENSES. Borrower shall pay all costs and expenses
incurred in connection with preparation for, closing, and servicing the Loan
including, without limitation, any legal fees, including the fees of Lender's
counsel, intangible taxes, documentary taxes, recording costs, and document
preparation fees.

         3. REPRESENTATIONS AND WARRANTIES. To induce Lender to make the Loan,
Borrower makes the following representations and warranties:

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            A. The financial information for Borrower and each guarantor or
other obligor furnished to Lender in connection with Borrower's application for
the Loan is complete and accurate. There has been no material nor adverse change
in the financial condition of either Borrower or any guarantor or other obligor
of the Loan from that reflected on such financial information.

            B. Borrower is a duly organized corporation, existing and in good
standing under the laws of the State of Florida, has corporate power to carry on
the business in which it is engaged, and the obtaining and performing of the
Loan has been duly authorized by all necessary actions of the board of directors
and shareholders of the corporation under applicable law, and do not and will
not violate any provisions of law or any of its organizational documents.

            C. The obtaining and performing of the Loan does not and will not
result in a breach of, constitute a default under, require any consent under, or
result in the creation of any lien, charge, or encumbrance upon any property of
Borrower pursuant to any instrument, order, or other agreement to which Borrower
is a party or by which Borrower, any of its officers as such, or any of its
property is bound.

            D. There are no judgments, liens, encumbrances, or other security
interests outstanding against Borrower or any of its subsidiaries, or any of
their properties other than those disclosed to Lender in connection with
Borrower's request for the Loan, nor is there any pending or threatened
litigation that could or will give rise to any such judgment, lien or
encumbrance.

            E. Neither Borrower nor any of its subsidiaries have incurred any
debts, liabilities, or obligations (whether direct or contingent) nor committed
themselves to incur any debts, liabilities, or obligations other than those
disclosed to Lender in connection with Borrower's request for the Loan or shown
on the financial statements submitted to Lender.

            F. Neither Borrower nor any of its subsidiaries have made any
assignment for the benefit of their creditors, admitted in writing their
inability to pay their debts as they become due, filed a petition of bankruptcy
or been adjudicated bankrupt or insolvent, or filed a petition seeking any
reorganization, arrangement, composition, readjustment, liquidation,
dissolution, receivership or similar relief under any statute, law or
regulation.

            G. There are no actions, suits or proceedings pending or, threatened
against or affecting Borrower or any of its subsidiaries, the Collateral or any
guarantor or obligor on the Loan, or involving the validity or enforceability of
the Security Agreement or the priority of the lien thereof, at law or in equity,
or before or by any governmental authorities, and neither Borrower nor any of
its subsidiaries is in default with respect to any order, writ, injunction,
decree or demand of any court or any governmental authority.

            H. The obtaining of the Loan and the consummation of all other
transactions contemplated by the Loan Documents, and performance under the Loan
Documents, will not result in any breach of, or constitute a default under, any
mortgage, indenture, security agreement, lease, loan, credit agreement or any
other contract or instrument to which the

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Borrower or any of its subsidiaries is a party or by which their properties may
be bound or affected.

         4. GUARANTORS' REPRESENTATIONS AND WARRANTIES. To induce Lender to make
the Loan, each Guarantor makes the following representations and warranties:

            A. The financial information for each Guarantor furnished to Lender
in connection with Borrower's application for the Loan is complete and accurate.
There has been no material nor adverse change in the financial condition of any
Guarantor from that reflected on such financial information.

            B. The obtaining and performing of the Loan does not and will not
result in a breach of, constitute a default under, require any consent under, or
result in the creation of any lien, charge, or encumbrance upon any property of
any Guarantor pursuant to any instrument, order, or other agreement to which a
Guarantor is a party or by which a Guarantor or any of its property is bound.

            C. There are no judgments, liens, encumbrances, or other security
interests outstanding against a Guarantor or any of its property other than
those disclosed to Lender in connection with Borrower's request for the Loan,
nor is there any pending or threatened litigation that could or will give rise
to any such judgment, lien or encumbrance.

            D. No Guarantor has incurred any debts, liabilities, or obligations
(whether direct or contingent) and has not committed to incur any debts,
liabilities, or obligations other than those disclosed to Lender in connection
with Borrower's request for the Loan or shown on the financial statements
submitted to Lender.

            E. No Guarantor has made any assignment for the benefit of his
creditors, admitted in writing its inability to pay its debts as they become
due, filed a petition of bankruptcy or been adjudicated bankrupt or insolvent,
or filed a petition seeking any reorganization, arrangement, composition,
readjustment, liquidation, dissolution, receivership or similar relief under any
statute, law or regulation.

            F. There are no actions, suits or proceedings pending or, threatened
against or affecting any Guarantor, at law or in equity, or before or by any
governmental authorities, and neither Borrower nor any Guarantor is in default
with respect to any order, writ, injunction, decree or demand of any court or
any governmental authority.

            G. The obtaining of the Loan and the consummation of all other
transactions contemplated by the Loan Documents, and performance under the Loan
Documents, will not result in any breach of, or constitute a default under, any
mortgage, indenture, security agreement, lease, loan, credit agreement or any
other contract or instrument to which any Guarantor is a party or by which its
property may be bound or affected.

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         5. AFFIRMATIVE COVENANTS. Borrower will:

            A. Preserve and keep in force all licenses, permits, and franchises
necessary for the proper conduct of its business and duly pay and discharge all
taxes, assessments, and governmental charges upon Borrower or against Borrower's
property before the date on which penalties attach thereto, unless and to the
extent only that the same shall be contested in good faith and by appropriate
proceedings.

            B. Furnish to Lender (i) within 90 days after the close of each
fiscal year a consolidated annual profit and loss statement and balance sheet on
Borrower and its subsidiaries reviewed by an independent certified public
accountant who is satisfactory to Lender; (ii) within 30 days after filing each
year, an executed copy of Borrower's Federal income tax return, and if any
extensions have been filed, copies of each Extension Notice shall be furnished
to Lender within 30 days of filing; and (iii) such other information reflecting
the financial condition of Borrower and/or its subsidiaries as Lender may
request from time to time.

            C. Permit any representative or agent of Lender to examine and audit
any or all of Borrower's books and records when requested by Lender.

            D. Inform Lender immediately of any material adverse change in the
financial condition of Borrower or any of its subsidiaries. Borrower will also
promptly inform Lender of any litigation or threatened litigation which might
substantially affect Borrower's financial condition.

            E. Maintain Borrower's property and equipment in a state of good
repair.

            F. Maintain Borrower's net working capital, on a consolidated basis
("Net Working Capital") in an amount not less than $2,000,000.00 and a current
ratio ("Current Ratio") of not less than 1.2:1.0 at all times during the term of
this Agreement. For the purposes of this Agreement, Net Working Capital shall
mean the excess of Borrower's current assets over current liabilities, on a
consolidated basis with its subsidiaries, which shall be determined in
accordance with generally accepted accounting principles as consistently applied
in the preparation of Borrower's previous financial statements, and Current
Ratio shall mean the quotient of current assets divided by current liabilities,
on a consolidated basis with its subsidiaries.

            G. Maintain Borrower's maximum total liabilities to net worth ratio,
on a consolidated basis with its subsidiaries ("Tangible Net Worth") throughout
the term of the Loan at a minimum of 0.85:1.0 at all times during the term of
this Agreement. For the purposes of this Agreement, Tangible Net Worth shall
mean (i) the aggregate amount of assets shown on the balance sheet of Borrower
at any particular date (but excluding from such assets capitalized organization
and development costs, capitalized interest, debt discount and expense,
goodwill, patents, trademarks, copyrights, franchises, licenses, amounts due
from officers, directors, stockholders and affiliates, and such other assets as
are properly classified "intangible assets" under generally accepted accounting
principles) less (ii) liabilities at such date, all computed in accordance with
generally accepted accounting principles applied on a consistent basis.

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            H. Maintain Borrower's debt service coverage ratio, on a
consolidated basis with its subsidiaries ("Debt Service Coverage Ratio")
throughout the term of the Loan at a minimum of 1.2:1.0 on a calendar year basis
for all operations of the Borrower and its subsidiaries, computed as follows:
net profits plus interest, plus depreciation, all divided by interest plus
current maturities of long term debt and capitalized leases, plus unfunded
capital expenditures and advances/withdrawals made to shareholders of Borrower
and/or its subsidiaries.

            I. Maintain Borrower's Funded Debt to EBITDA ratio, on a
consolidated basis throughout the term of the Loan at a minimum of ______ at all
times during the term of this Agreement. "Funded Debt" means all outstanding
indebtedness for borrowed money and other interest-bearing indebtedness,
including current and long-term indebtedness. "EBITDA" means the sum of net
income before taxes, plus interest expense, plus depreciation, depletion,
amortization and other non-cash charges. This ratio will be calculated at the
end of each fiscal quarter, using the results of that quarter and each of the
three immediately proceeding quarters.

         6. GUARANTORS' AFFIRMATIVE COVENANTS. Each Guarantor will:

            A. Furnish to Lender (i) within 90 days after the close of each
calendar year, a personal financial statement, including income information and
contingent liabilities, certified to Lender; (ii) within 30 days after filing
each year, an executed copy of Guarantor's Federal income tax return; and (iii)
such other information reflecting the financial condition of Guarantor as Lender
may request from time to time. In the event such financial statements disclose a
material, adverse change in the financial condition of Guarantor from the
conditions set forth in any prior financial statement of Guarantor theretofore
furnished to Lender, same shall constitute a default which shall entitle Lender
to all of the rights and remedies provided for in the Note, Security Agreement,
or other Loan Documents.

            B. Permit any representative or agent of Lender to examine and audit
any or all of Guarantor's books and records when requested by Lender.

            C. Inform Lender immediately of any material adverse change in the
financial condition of Guarantor. Each Guarantor will also promptly inform
Lender of any litigation or threatened litigation which might substantially
affect such Guarantor's financial condition.

         7. NEGATIVE COVENANTS. Neither Borrower nor any of its subsidiaries
will, without prior written consent of Lender:

            A. Collaterally assign, mortgage, pledge, encumber, or grant any
security interest in any of its assets, whether now owned or hereafter acquired.

            B. Enter into any merger or consolidation, or sell, lease, transfer,
or otherwise dispose of all or any substantial part of its assets, whether now
owned or hereafter acquired.

            C. Change the name in which it does business.

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            D. Move its principal place of business without giving written
notice thereof to Lender at least 30 days prior thereto.

            E. Incur any new debt whether secured or unsecured, except trade
debt for the purchase of equipment which does not exceed $100,000.00 for any
item of equipment, and trade debt for the purchase of inventory.

            F. Execute any guarantees or assumptions of any debt, or endorse any
obligations, except that Borrower may guaranty any trade debt for the purchase
of equipment which does not exceed $100,000.00 for any item of equipment, and
trade debt for the purchase of inventory which is incurred by a subsidiary of
Borrower.

            G. Enter into any asset sale/leaseback arrangement.

            H. Cause or permit any change in management of Borrower's
operations.

         8. EVENTS OF DEFAULT. The Lender shall have the option to declare the
entire unpaid balance due on the Loan without notice of any kind, if any of the
following events occur:

            A. Failure or omission to pay, within fifteen (15) days after
payment is due, the Note (or any installment of principal or interest
thereunder).

            B. Default in the payment (other than payment of principal and
interest) or performance of any obligation, covenant, agreement or liability
contained or referred to in the Security Agreement, Loan Agreement, Note,
Guaranties, or any other Loan Document, or upon the existence or occurrence of
any circumstance or event deemed a default under the Note or any other Loan
Document.

            C. Any warranty, representation or statement made or furnished by
Borrower or Guarantors for the purpose of inducing Lender to make the Loan
proves to have been false in any material respect when made or furnished.

            D. The default by Borrower or any party obligated under the Note or
any guaranty thereof in the payment or performance of any obligation, covenant,
agreement, or liability contained in any other mortgage, note, obligation or
agreement held by Lender.

            E. The death, dissolution, termination of existence, insolvency, or
business failure of Borrower, or any party obligated under the Note or
Guaranties.

            F. The assignment for the benefit of creditors or the commencement
of any proceedings in bankruptcy or insolvency by or against Borrower or by or
against any person obligated under the Note or Guaranties.

            G. The determination by Lender that a material adverse change has
occurred in the financial condition of Borrower or any person obligated under
the Note or any guaranty

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thereof, from the conditions set forth in the most recent financial statement of
such person heretofore furnished to Lender or from the condition of such person
as heretofore most recently disclosed to Lender in any manner.

             H. The failure by Borrower or any party obligated under the Note or
Guaranties thereof to make any payment of principal or interest when due under
any obligation to any other creditor, if such failure continues beyond any
applicable grace period.

             I. Any substantial part of the inventory, equipment, or other
property of Borrower, real or personal, is damaged or destroyed and the damage
or destruction is not covered by collectible insurance.

             J. Borrower suffers or permits any lien, encumbrance, or security
interest to arise or attach to any of Borrower's property, which is not
satisfied within 30 days.

             K. Any judgment is entered against Borrower that is not satisfied
or appealed within 30 days.

             L. Falsity in any material respect of, or any material omission in,
any representation or statement made to Lender by or on behalf of Borrower or
any person obligated under the Note or any guaranty thereof, in connection with
the Loan.

         9.  REMEDIES UPON DEFAULT. Upon the occurrence, or the discovery by
Lender of the occurrence, of any of the foregoing events, circumstances, or
conditions of default, Lender shall have, in addition to its option to
accelerate to maturity the full unpaid balance of the Loan, all of the rights
and remedies under applicable law, and in addition shall have the following
specific rights and remedies:

             A. To exercise Lender's right of set-off against any account, fund,
or property of any kind, tangible or intangible, belonging to Borrower which
shall be in Lender's possession or under its control.

             B. To cure such defaults, with the result that all costs and
expenses incurred or paid by Lender in effecting such cure shall be additional
charges on the Loan, shall bear interest at the highest rate permitted by law,
and shall be payable upon demand, and shall be secured by the Security Agreement
and other Loan Documents.

         10. ATTORNEYS' FEES AND COSTS. Borrower promises and agrees to pay all
costs of collection and attorneys' fees, including fees for appellate
proceedings, bankruptcy proceedings or otherwise, incurred or paid by Lender in
enforcing this Agreement or preserving any right or interest of Lender
hereunder.

         11. WAIVER. No failure or delay on the part of Lender in exercising any
power or right hereunder, and no failure of Lender to give Borrower notice of a
default hereunder, shall operate as a waiver thereof, nor shall any single or
partial exercise of any such right or power preclude any other or further
exercise thereof or the exercise of any other right or power

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hereunder. No modification or waiver of any provision of this Agreement or any
instrument executed pursuant hereto or consent to any departure by Borrower from
this Agreement or such instrument shall in any event be effective unless the
same shall be in writing, and such waiver or consent shall be effective only in
the specific instance and for the particular purpose for which given.

         12. BENEFIT. This Agreement shall be binding upon and inure to the
benefit of Borrower and Lender and their respective successors and assigns.
Lender may assign this Agreement in whole or in part. Borrower may not assign
this Agreement or its obligations hereunder without Lender's written consent.

         13. GOVERNING LAW. This Agreement shall be governed and construed in
accordance with the laws of the State of Florida, and any litigation arising out
of or relating to this Agreement or the Loan shall be commenced and conducted in
the courts of the State of Florida or in the federal courts of the State of
Florida.

         IN WITNESS WHEREOF, the parties hereto have executed this Loan
Agreement on the day and year first above written.

                                       SUN HYDRAULICS CORPORATION,
                                       a Florida corporation

                                       By: /s/ Richard J. Dobbyn
                                           ----------------------------------
                                               Richard J. Dobbyn
                                               As its Chief Financial Officer

                                                      BORROWER

                                       NORTHERN TRUST BANK OF FLORIDA, N.A.

                                       By: /s/ Terence E. McGannon
                                           ----------------------------------
                                               Terence E. McGannon
                                               As its Vice President

                                                      LENDER

                                       SUN HYDRAULIK HOLDINGS LIMITED,
                                       a ________________________

                                       By:
                                           ----------------------------------
                                               Clyde Nixon
                                               As its

                                       SUN HYDRAULIKS LIMITED,
                                       a corporation organized under the laws
                                       of the United Kingdom

                                       By:
                                           ----------------------------------
                                               Clyde Nixon
                                               As its

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                                       SUN HYDRAULIK GmbH,
                                       a corporation organized under the laws
                                       of Germany

                                       By:
                                           ----------------------------------
                                               Clyde Nixon
                                               As its

                                                      GUARANTORS

                                       9<PAGE>   1
                                                                    Exhibit 4.31

                      FIRST AMENDMENT TO SECURITY AGREEMENT

         THIS FIRST AMENDMENT TO SECURITY AGREEMENT made on July 23, 2000, by
and between SUN HYDRAULICS CORPORATION, a Florida corporation ("Debtor"), and
NORTHERN TRUST BANK OF FLORIDA, N.A. ("Secured Party").

                              W I T N E S S E T H :

         WHEREAS, Debtor is the borrower under an existing loan ("Loan") from
Secured Party in the principal amount of $7,500,000.00, which is currently
evidenced by a noted dated July 23, 1999 payable as provided therein ("Note"),
and

         WHEREAS, the Loan is secured by certain property described in the
security agreement entered into between Debtor and Secured Party dated July 23,
1999 ("Security Agreement"), and

         WHEREAS, Debtor is also the borrower under an existing revolving line
of credit loan in the amount of $5,000,000.00 made by Secured Party to Debtor
and evidenced by a renewal master note dated July 23, 1999 ("Master Renewal
Note"), which existing revolving line of credit loan and Master Renewal Note are
referenced in the default paragraph contained on page 2 of the Security
Agreement, and

         WHEREAS, Debtor has requested that Secured Party renew and increase the
existing line of credit loan, and Secured Party has agreed to do so provided
Debtor, among other things, enter into this First Amendment to Security
Agreement.

         NOW, THEREFORE, in consideration of the premises and of the covenants
and agreements herein contained and the agreement by Secured Party to renew and
increase the revolving line of credit, the parties hereto agree as follows:

         1. Subparagraph (f) of the "default" paragraph contained in the second
full paragraph on page 2 of the Security Agreement is hereby amended in its
entirety and the following substituted therefor:

            f. The default by Debtor or any party obligated under the Note or
any Guaranty thereof in the payment or performance of any obligation, covenant,
agreement, or liability contained in any other mortgage, note, obligation or
agreement held by Secured Party, including but not limited to that certain
revolving line of credit loan in the amount of $7,500,000 made by Secured Party
to Debtor and evidenced by Renewal Master Note dated ________, 2000.

         2. Except as specifically amended hereby, all of the terms, covenants,
and conditions of the Security Agreement shall remain in full force and effect.

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         IN WITNESS WHEREOF, the parties hereto have executed this First
Amendment to Security Agreement on the day and year first above written.

                                         SUN HYDRAULICS CORPORATION,
                                         a Florida corporation

                                         By: /s/ Richard J. Dobbyn
                                             ----------------------------------
                                                 Richard J. Dobbyn
                                                 As its Chief Financial Officer

                                                        DEBTOR

                                         NORTHERN TRUST BANK OF FLORIDA, N.A.

                                         By: /s/ Terence E. McGannon
                                             ----------------------------------
                                                 Terence E. McGannon
                                                 As its Vice President

                                                    SECURED PARTY

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