Engine/Transmission (1998.5 - 2002) Vacumn Pump??

[LCampbell]

Two days ago my truck operated fine. Today I started it up to go somewhere & realized just as I tried to drive off that I had no power steering or brakes. I was thinking it might be the vacumn pump but there are no visible oil leaks around it & it appears to be making good vacumn when I removed the hose from the top & put my finger on it. Am I looking in the right direction or should I be looking at something else. I'll put a vacumn gage on it later today.

The truck is a 2002 2500 with an automatic transmission with approx 120,000 miles on it.

Thanks

 

[LCampbell]

Disregard my previous post. I looked a little closer. I thought both systems may of had a vacumn assist but more than likely I had a brain fart. When I pulled the dip stick out of the powersteering pump the fluid ran out on the ground. The last time I checked it it was the proper level now it's at the top of the neck.

 

[Ram4Sam]

All the vacuum pump does is provide vacuum for the HVAC system, our trucks use the hydro boost(power steering pump) for steering and braking.



Sam

 

[DFerverda]

If you have bubbles and the fluid is being pushed out, i would bet on a bad hydro boost (beside the brake master cylinder) with the blue canister on it.
When it is going south, the canister pushes air into the system and does what you describe.
Make sure if you replace it, the rod to the master cylinder is the same length, and you will need to keep the 1 inch thick piece the master bolts to for the new one.
Dirk

 

[DLausche]

If the PS fluid was high all of a sudden then something is amiss. One thing I would suspect is that the nitrogen canister has burped a bunch of gas into the hydraulic system. When this happens it usually results in a big puddle of PS fluid on the ground under the truck and then you have low fluid level after that. You may have just had a lot of air bubbles in there which could cause the PS pump to not build pressure. Did the fluid look frothy at all when you checked it? This is a clear sign of the nitrogen canister burping it's charge into the lines. If this is the cause then I would not worry about it too much. Just check and correct the fluid level for a few days and all should be fine.



If the power steering and brakes do not come back after verifying correct fluid level then something else is up...



-Deon

 

[LCampbell]

Thanks for the responses. After I submitted the thread I did a little reading in the forum regarding this so I proceeded to siphon most of the fluid out of the resevoir & then removed the small strainer/check valve from the pump. It was reasonably clean. So I cleaned it up & reinstalled it, refilled the resevoir & started it up. Tried to turn the wheel both ways. It was very hard. Shut it down, checked the level again & topped it up as it had gone down some & started the engine again & tried to steer left/right. It's still very hard to move Any ideas. I'm thinking I have to bite the bullet & replace the pump

 

[hsmith]

The vacuum pump seal can blow, leak, and overfill the ps reservoir with engine oil.

 

[ata]

Jack the front tires off the ground. Put jack stands under truck. Start the engine then turn the steering wheel lock to lock (left-right). This will take lots off turns you have to work the nitrogen out of the system. You will have to put fluid to keep it up to level. If this does not work the pump has gone bad. NOW READ THIS! With the nitrogen can blown you will NOT have BRAKES (very hard pedal) with the engine not running. So you are going to have to change out the Hydro-Booster to make the truck right.

 

[ata]

The vacuum pump seal can blow, leak, and overfill the ps reservoir with engine oil.

The power steering pump is mounted to the vacum pump by an adapter separating the two. There is an open air space between the two units.

 

[LCampbell]

Jack the front tires off the ground. Put jack stands under truck. Start the engine then turn the steering wheel lock to lock (left-right). This will take lots off turns you have to work the nitrogen out of the system. You will have to put fluid to keep it up to level. If this does not work the pump has gone bad. NOW READ THIS! With the nitrogen can blown you will NOT have BRAKES (very hard pedal) with the engine not running. So you are going to have to change out the Hydro-Booster to make the truck right.

I did a little more reading about pump failures on the forum & then started the truck again but this time I reve'd it up to to about 1800 rpm & the steering started working normally. I worked it left & right & checked the fluid level again & it was down some so I topped it off. I took it for a short drive thru the neighbourhood & the brakes & steering are working normally even at idle rpm. The fluid level was still ok after I shut it down. I'll check for hard brakes in the morning. Sure hope I don't have to replace the hydro-booster

 

[hsmith]

Maybe so on yours, but not mine. No "open" space at all between them.