Im a new guy on this forum, This is my first post and hope to exchange a lot of infro on this site, Any way I have been tyring to figure out an annoying leak comming from ps pump out the cap for months, The pump seems to Be genarating fluid and overflowing out cap. I can drain pump down a bit and it wont leak for awhile, then about a few hundres miles later it gains a few ounces and pukes it out cap, and of course makes a mess everywhere. I have already changed fluid (put ps fluid back in) and bled system, so I know those ideas wont help, I rebuilt vacuum pump about 150,00 miles ago, and there is no external leakage. The oil comming out of pump is real black, Is it possable for engine oil to seep in there internaly. There is no external leakage around hydroboost, but my brakes dont seem to have the poiwer assist they used to, and my steering seems fine. So any ideas would be helpfull before I start replacing parts that I dont have to.

I'd like to say welcome to the forum! Sorry I have unresolved power steering issues myself. Hopefully some more guys will join in soon.

Sounds like the engine oil is getting into the power steering through the front seal of the power steering pump. Sounds like you might be due for a pump change. I would flush the system out before you hook up the return lines to be sure to flush the engine oil back out.

Thanks for the infro, Hopefuly I can change pump out this week. That would be a easy fix, what about the seal in vac pump,? It does not show any signs of leaking. It just confuses me how engine oil gets in there

Apparently the oil is getting push past the seal into the pump if the power steering fluid is black with engine oil. I've never really paid attention to the seal placement is it riding on the input shaft or what... But some how your getting oil into the power steering. Unless the power steering system is that contaminated.

 

Still scratching my head.

I see no other reason for fluid level going up. Kinda like the old block mounted fuel pumps leaking gas into motor.

I see no other reason for fluid level going up. Kinda like the old block mounted fuel pumps leaking gas into motor.

 

The oil comming out of pump is real black

 

The only thing I can think of is engine oil. Nothing else near it.

Brake fluid level staying full ?

Brake fluid level staying full ?

That was another concern, It was going down a bit, but it ended up being a leaky wheel cylinder on the rear, Got that fixed and seems to be staying full, at first I thought it may be mixing in at the hydro boost

Any external seal leaks on the steering sector gear hoses ect. this can cause air In the system and cause foam and over flow but after it cools and separates again it will be a bit low.

Mine over flowed a few months back. It hasn't since and I have no idea why.

OK, Here's what I decided to do, I went down to orielys, picked up a new pump and then to the local cummins dealer and got a seal kit for the vac pump, I figured while I'm down there I might as well cover all bases,  Ill let you know how it turns out.

Sounds like a good plan.

make sure when you rebuild the vac pump you get the seal sleeve to steering pump collet pushed in the same depth as before or the steer pump wont bolt back up

I just changed out ps pump. and I'm glad I decided to do vac pump seals, because the seal on the vac pump was butchered, I have no idea why it wasn't leaking externally, but got it back together, and bled out, no signs of overflow so far, and I poured about 2.5 quarts of ps fluid through before it started to clear up.

Well I just went outside and my power steering is overflowing again. The pattern I'm seeing the same as last time is the truck has sat for days with no use and a warming up temperature change outside from the last few days of cold.

Not to be silly, but, how full are you filling it? And what brand of Ps fluid?

I never added any from the last time it did it. I think I will this time it's right at the bottom of the cold mark.

Mine did this too.... I think I overfilled it a bit though. It's amazing just how much the fluid expands when it's hot. I'd wash it, don't add any and see what it looks like after another drive. 

I just got back from a 1000 mile trip to Roosevelt lake in central Arizona, I double towed my 10,000 lb fifth wheel and bass boat, and with all the steep grades Colorado and Arizona has to offer my baby didn't miss a beat. and my power steering issue is gone. I am 100% sure it was sucking in engine oil form the seal in the vac pump and the ps pump. As for filling it I just jacked front wheels off ground, disconnected line at hydroboost and ran it into a container. As my kid worked steering back and forth I kept pouring in until fluid cam out clean. I just wanted to make sure I got all the old crap completely out of system.

Again haven't used the truck this week, been on vacation , and the power steering has leaked out the cap. Very odd. I'm kind of getting used to it happening if I don't use it. I think she's getting back at me for leaving her alone for to many days.