Just completed a 400 mile trip got 15 miles from the house and decided to stop and fill up. I noticed when I was easing up to the pump that my brake felt different. Filled up, when to pull away and no power brakes and no power steering. Is this the vac pump? Hydro boooster? HELP

Sam

 

Lack of brakes and steering would point to the pwr steer pump.

 

Many (including myself) have reported a temporary loss of power steering and brake assist. In my case, it went away in a few seconds and never came back. Others have said it has happened several times. It seems to usually happen right after start up. Most said it went away after giving the truck some throttle. I have not heard of anyone having a complete failure, so I also have not heard what the problem turned out to be. Several people have had good ideas as to what it may be, but I think it is still somewhat of a mystery.

 

Let this be your 1st of a complete failure. I checked everything for leaks while I was at the station. Fired it up, shut it down a couple of times then muscled her on home braking mostly with 2nd and 3rd gear. Any other pionters anyone?

 

WOW, I didn't realize that you were still having the problem. Maybe you will be able to answer this for the rest of us.

Like J Body said, the power steering pump is the most likely culprit. It really is the only common link between the power steering and power brakes that I can think of.

 

Thanks J Body I guess I'll start by tearing into the p/s pump in the morning.

 

I'm sure you already checked, but is the drive belt still intact? Otherwise, p/s pump.

 

the diesel does not use a belt to drive the power steering.

 

It might be a broken shaft on the power steering pump worse case, or a stuck controll valve that is not allowing fluid to pass. If I remember it goes from pump to PB actuator then to the steering box. I talked to the guy at www.hydroboost.com and he said the the shaft necks down in one area. We both thought it to be a safety feature in that if the pump locks it will snap the shaft instead of harming the engine. Another thing is that the pump gets shaken to death due to the fact that it is direct driven off the engine. A belt would normally absorb harmonics and other vibrations. O and with the engine off the nitrogen canister should seem like its welded to the actuator (behind the MC), if you can wiggle it the actuator is bad. When I dont have assisted brakes but have power steering, I can feel the brakes "kick in" by a small amount of feedback in the steering wheel. This is more dominant if I am making a turn when the power brakes decide to be power again. keep us informed on whats up.

 

Tore into it after I picked up a new pump and of course the old pump is fine but the tangs on the vacuum pump were sheared. can the pin be pushed out and the end be replaced or am I about to meet the reaper at the parts dept? help!!!

FYI was told by the dealership today that my truck only came with a 3/36 warranty but when it was being sold they were awfully proud of some 70k bull...

Sam

 

Sorry for your problems. As far as the warranty, I was told by my dealer that the vacuum pump is not covered under the engine warranty even though it is bolted to the engine, is gear driven off the engine, and even shares engine oil.

If you are able to repair the shaft on your pump, take this opportunity to replace the seal and o-rings in the vacuum pump and hopefully save yourself a repair down the road.

 

ok thanks. any ideas where/how to get the pump repaired??????

 

My local Cummins dealer repaired mine. I would assume that a good hydraulics shop could take care of you also. I was just looking at my service manual for you, and even though it does not specifically talk about replacing the tang adapters, if there is a roll pin that attaches it to the end, I see no reason why you couldn't replace just that part. It may not be available through Dodge, but I would bet that it is available through Cummins.

 

Anyone else ever ran into this? Should I go ahead and put the new p/s pump in prior to re-assembly (it appears to be fine and in working order) but I don't want to go thru all of this again and find out it was due to another problem. Maybe a bad tang coupler from the start or what? The p/s pump looks new. Being from the electric motor business it just appears awfully strange to shear tangs when no apparent stress is evident on the assembly. Is this correct or does the p/s pump have times to where it incurrs an exessive amount of force at 70 degrees F ambient temp.?

 

there are rebuilt vacuum pps on EBAY there is also a rebuild kit for 60$ on EBAy.