Engine/Transmission (1998.5 - 2002) Hydraulic pump died, and replacements don't work!

[Vaughn MacKenzie]

A friend is having grief with his '99 quadcab 4x4. His PS/brake pump died, leaking oil on the ground, without warning. Truck only has 33,000 miles.



He's replaced it with 2 remans and neither one works out of the box. We tried bench mounting them and filling them with oil, hooking up the outlet hose and spinning it with a drill. Doesn't pump a drop.



Can someone with a service manual look up and see if there is some special priming or bleeding procedure when R&R-ing a hydraulic pump? Shouldn't they work on the bench tested as above?



He took apart the original and it was pretty filthy and gooked up with black residue. It would be a good idea to flush the system every 20-30,000 miles or once a year as a good preventive measure. I did that on my '01 and never had a lick of trouble in 87,000 miles. I used Valvoline semi synthetic.



Vaughn

 

[csutton7]

usually the only thing needed is to jack the front end off the ground and turn the wheels lock to lock like 40-50 times to bleed the air bubbles out of the system---you might also try revving the engine to 2500-3000 rpms, this has worked in the past----are the lines reconnnected to their respective places???----I don't think there's much more one can do

 

[Vaughn MacKenzie]

From the way the pump is designed, the return hoses just dump oil into the open chamber there, and the pump draws from this chamber to pump the fluid. It looks like it should pump something sitting there on the bench with a full chamber of fluid. We even dumped oil all around the vanes so they'd get a good seal before putting it together.



There is a spring-loaded check-valve and pressure relief valve combined into one piece. I am thinking this is the likely source of the problem, a part easily removed without having to remove the pump from the truck. But not being a hydraulics expert or knowing how the check/pressure relief valve works it's hard to tell if that's the source of the problem.



Vaughn

 

[Chipstien]

Vaughn, I have tried 3 reman pumps and not one worked as good as the original. And that was going step by step to the factory service manual. Needless to say I got my money back. Seems the only way is to buy a new pump from Cummins or the dealer. Think someone listed that the new one at Cummins runs around $304. I can't for the life of me figure out why reman pumps are not working... ... anyone know?

 

[Vaughn MacKenzie]

Chipstien what instructions did the manual give? These things won't move a drop of oil!



Vaughn

 

[Vaughn MacKenzie]

MBPerk of Northwest Bombers passed this on to me. Thanks man!



John Engstrom here you go. . .

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BOOSTER FUNCTION TEST

With the engine off depress the brake pedal several

times to discharge the accumulator. Then depress the

brake pedal using 40 lbs. of force and start the

engine. The brake pedal should fall and then push

back against your foot. This indicates the booster is

operating properly.



ACCUMULATOR LEAKDOWN

(1) Start the engine, apply the brakes and turn the

steering wheel from lock to lock. This will ensure the

accumulator is charged. Turn off the engine and let

the vehicle sit for one hour. After one hour there

should be at least two power assisted brake application

with the engine off. If the system does not retain

a charge the booster must be replaced.



(2) With the engine off depress the brake pedal

several times to discharge the accumulator. Grasp

the accumulator and see if it wobbles or turns. If it

does the accumulator has lost a gas charge and the

booster must be replaced.



SEAL LEAKAGE

If the booster leaks from any of the seals the booster assembly must be replaced (Fig. 25).

² INPUT ROD SEAL: Fluid leakage from rear end of the booster.

² PISTON SEAL: Fluid leakage from vent at front of booster.

² HOUSING SEAL: Fluid leakage between housing and housing cover.

² SPOOL VALVE SEAL: Fluid leakage near spool plug.

² RETURN PORT FITTING SEAL: Fluid leakage from port fitting.



STANDARD PROCEDURE - BLEEDING

The hydraulic booster is generally self-bleeding, this procedure will normally bleed the air from the booster. Normal driving and operation of the unit will remove any remaining trapped air.

(1) Fill power steering pump reservoir.

(2) Disconnect fuel shutdown relay and crank the engine for several seconds, Refer to Fuel System for relay location and WARNING.

(3) Check fluid level and add if necessary.

(4) Connect fuel shutdown relay and start the engine.

(5) Turn the steering wheel slowly from lock to lock twice.

(6) Stop the engine and discharge the accumulator by depressing the brake pedal 5 times.

(7) Start the engine and turn the steering wheel slowly from lock to lock twice.

(8) Turn off the engine and check fluid level and add if ecessary.

NOTE: If fluid foaming occurs, wait for foam to dissipate and repeat steps 7 and 8.



STANDARD PROCEDURE - POWER STEERING

PUMP - INITIAL OPERATION

WARNING: THE FLUID LEVEL SHOULD BE CHECKED WITH ENGINE OFF TO PREVENT INJURY FROM MOVING COMPONENTS.

CAUTION: Use MOPAR Power Steering Fluid or

equivalent. Do not use automatic transmission fluid and do not overfill.

Wipe filler cap clean, then check the fluid level. The dipstick should indicate COLD when the fluid is at normal temperature.

(1) Turn steering wheel all the way to the left

(2) Fill the pump fluid reservoir to the proper level and let the fluid settle for at least two (2) minutes.

(3) Raise the front wheels off the ground.

(4) Slowly turn the steering wheel lock-to-lock 20 times with the engine off while checking the fluid level.



NOTE: Vehicles with long return lines or oil coolers

turn wheel 40 times.

(5) Start the engine. With the engine idling maintain the fluid level.

(6) Lower the front wheels and let the engine idle for two minutes.

(7) Turn the steering wheel in both direction and verify power assist and quit operation of the pump. If the fluid is extremely foamy or milky looking, allow the vehicle to stand a few minutes and repeat the procedure.

 

[vette75406]

Try going to agrsteering.com they are a performance steering builder they have a Super Pump #822256 for 169. 00 fits 94-2002 dodge cummins ,should help your problem. I'ts the one im going to get when mine fails , the problem I have is no assist at parking speed which is suposed to be pressure rpm/related.







_________________________

2000 4X4 QC LB AUTO 3. 54 HUSKY LINERS ,LIGHTFORCE140'S

MAGNAFLOW POLISHED EXHAUST IN THE MAIL FROM RIP ROOK

 

[Texas Diesel]

I had the same problem once. I filled the PS reservoir with fluid and used a vaccum gun to pull the air through and get fluid in the system. Worked perfectly. Problem is the pump is cavitating and you need to get the air out. You might try loosening the high pressure line to the hydrobooster to lessen back pressure on the pump. Also, it will growl for an hour or so until all the air bubbles work their way out.