[OCMDGTO]

My power steering cap comes off/loosens up when I run the car hard. If I drive slow/low rpms it isn't a problem. It's a standard PS pump that works great from Ames and I've tried several different caps. I have lost a few that were gone when I came home. The best seems to be the style with the diaphragm since it will loosen up but can't fall off. Anybody else experiencing this? I've never had this problem on any of my old cars.

[chuckies76ta]

I've never had one come off, but I just bought a new pump from Tuff stuff through Summit and I have to put a glove on to remove the cap. It's the opposite of yours. Sounds like you might need a new cap. It should snap tight on the last turn.

[JLMounce]

Is the cap physically loosening up / coming off or is it puking fluid?

The former would be pretty rare as the caps lock/snap into place. Puking fluid when the car is being run hard is somewhat common as the cap is also the vent.

You’ll commonly see people run rags around the caps in auto-x and road race situations.

It might be a bit over kill but Lee Power Steering makes a remote reservoir system with a vented can that solves this issue on type I pumps. It’s a bit spendy at around $500 bucks but if you’re running your type I pump pretty hard, it may be your solution.

[OCMDGTO]

JL the cap loosens itself up somehow, no puking. I've tried at least a half dozen caps. Chuck I wish I had that "problem" and I'm definitely not spending $500 on it. I'll use duct tape before that.

[Holeshot71]

I’m having the same problem. I’m starting to think it’s vibrations and maybe the air/fan blowing across the front of the engine at high speeds causes it to loosen? I haven’t lost the cap or any fluid so I haven’t done much about it except snug the cap once in a while lol.

[grivera]

Originally Posted by OCMDGTO

JL the cap loosens itself up somehow, no puking. I've tried at least a half dozen caps. Chuck I wish I had that "problem" and I'm definitely not spending $500 on it. I'll use duct tape before that.

Maybe an issue with the reservoir? I've used several rebuilt pumps without issue. The current one is from Advance Auto and I modified it for slightly higher pressure and more flow.

[JLMounce]

Originally Posted by grivera

Maybe an issue with the reservoir? I've used several rebuilt pumps without issue. The current one is from Advance Auto and I modified it for slightly higher pressure and more flow.

Yes, OP if this is happening with all sorts of different caps, I would suspect the reservoir at that point. I would look to replace the reservoir.

[OCMDGTO]

I thought about that but the cheapskate in me has a hard time getting rid of something that works

[JLMounce]

Originally Posted by OCMDGTO

I thought about that but the cheapskate in me has a hard time getting rid of something that works

If it can't fasten the cap, does it work?

The way I see it, this is both a maintenance and safety item. The pump and reservoir is likely over 50 years old. Things wear out. If the cap is dislodging itself and you're puking fluid, that's a fire risk. Especially considering the proximity of the reservoir to the exhaust.

I'd hate to see a beautiful classic taken down because of a failed $100.00 part.

[OCMDGTO]

Great point JL

[steve25]

I have found that at high rev's ( 4000 or more ) those dam type of notched belts your running put a lot of vibration into a pulley, especially a big diameter pulley like they use on pumps.

Just for S & G I would try a regular good old V belt!

[OCMDGTO]

Steve where are you getting them? This is pretty much all that's available locally

[Formulajones]

Dad lost his PS cap on his 69 GTO at the dragstrip. Went out to make a pass, came back to the pits and the cap was gone.

Odd thing I've never had happen before. His was original reservoir and cap. I assume vibration, maybe age, had something to do with it.

I shoved a shop rag in it and he raced the rest of the day LOL

Later bought a new cap to put on and it's been fine ever since.

[dataway]

Gotta be vibration right? The way the caps go on it seems like enough pressure to blow the cap off would a: spray tons of fluid all over b: probably explode or blow the seals out of the reservoir.

[JLMounce]

I would think if there is an absence of fluid, that it would have to be vibration. The cap should twist and "lock" into place. The caps are vented, so it shouldn't be pressure.

[OCMDGTO]

Definitely vibration. It would still have plenty of fluid in it when the cap came off. Thanks for the replies

[JLMounce]

Chris, I'd turn that thing on, and give it some decent rpm from under the hood. See what kind of vibration you may be looking at.

To steve25's point, this issue could be as simple as a belt change.

[steve25]

Go to a lawn mover repair shop and try and get a Gates brand green strip belt close to yours.

Bring the belt your using now with you.

[Kenth]

I would use the correct 1/2" width belt for the PS pump.

[geeteeohguy]

Originally Posted by Kenth

I would use the correct 1/2" width belt for the PS pump.

This^^^^. The current belt is too small and will vibrate at high rpm and could be the cause of your issue. Fix what's obviously wrong first.