Power Steering & Hydroboost Bubbles

[RonJones]

This last weekend, I drove my ‘73 EB with Saginaw pump and 1999 Ford Mustang Cobra hydroboost (Cardone 52-7360) out of its relatively warm 40 deg garage, and parked it outside in 15 deg weather for a few hours. When I returned and put it back in the garage, I heard that familiar groan from the power steering that it had air in the system. I perservered and got it parked inside, and sure enough I found later a big puddle of presumed bubbled over power steering fluid (marked with UV dye to find leaks) under the truck. I jacked the front axle up so the right wheel was just barely touching, started the engine and moved the steering wheel a back and forth a bit - no bubbles in the Saginaw pump. Hit the brakes, loud groan, and many, many bublbles.

I’ve never had this kind of issue that cold could cause frothing of the power steering fluid. Does this mean I have a bad seal in the hydroboost, or what?

Thanks.

 

[Yeller]

Just cold fluid, it gets thick and doesn't flow fast enough. Clean up the mess and refill it will be fine. The bubbles are in the hydroboost from starting it with your foot on the brake, the first thing the system does is cavitate from the thick fluid which immediately goes straight to the accumulator on the hydroboost. It will need to run and be circulated some to get the bubbles out. Starting the engine and letting it warm up isn't just for the engine, it is for the power steering and transmission too.

 

[gnpenning]

The fluid we use for our snow plows are formulated for extreme cold . You definitely need to allow some warm up time or you will be having difficulty turning with the weight of the plow hanging off the front.

While I've never checked into it, the cold we have had this winter has me wondering if it could be used in the ps system??

 

[RonJones]

The fluid we use for our snow plows are formulated for extreme cold . You definitely need to allow some warm up time or you will be having difficulty turning with the weight of the plow hanging off the front.

While I've never checked into it, the cold we have had this winter has me wondering if it could be used in the ps system??

That’s interesting, what’s the brand and the specification?

 

[RonJones]

Just cold fluid, it gets thick and doesn't flow fast enough. Clean up the mess and refill it will be fine. The bubbles are in the hydroboost from starting it with your foot on the brake, the first thing the system does is cavitate from the thick fluid which immediately goes straight to the accumulator on the hydroboost. It will need to run and be circulated some to get the bubbles out. Starting the engine and letting it warm up isn't just for the engine, it is for the power steering and transmission too.

I gave it three tries on three separate days with an afternoon ambient temp of 60 deg, and every time I push on the brake, groan. Perhaps there are still trapped bubbles in the accumulator reservoir, but I don’t recall the hydroboost ever making that noise, even with a fresh dry bones install. I’ll go through the bleeding process and see what shakes out.

 

[Yeller]

It’s just begging for a drive, I’m assuming you’ve got salt down and it’s not advisable. But a 30 minute drive would fix it and if your like many of us, do your soul some good.

 

[RonJones]

It’s just begging for a drive, I’m assuming you’ve got salt down and it’s not advisable. But a 30 minute drive would fix it and if your like many of us, do your soul some good.

Is this the self-bleeding concept?

 

[gnpenning]

That’s interesting, what’s the brand and the specification?

In the past I've bought the Boss brand.

I just bought 4 quarts of this brand and put it in just before the cold spell with no issues. Due to the location of the pump and reservoir I drain every year. Water in the system becomes ice.

Dump trailers use the same basic electric over hydraulic setup as plows. Plows just add more cylinders and valves.

 

[Viperwolf1]

Maybe not enough fluid in the reservoir. Sounds like the level is dropping and allowing air to enter the pump.

 

[nvrstuk]

NOT a bubble till you hit the brakes then FULL of bubbles? Either had air b4 or air got introduced when you hit the brakes is my thought.

Take it for a drive like Steve said but I'd try not to hit the brakes for the first couple miles, check teh fluid for bubbles then try hitting the brakes a dozen times in the next mile.

 

[EPB72]

You can also look from inside vehicle the back of the hydtoboost for any fluid ay the input pushrod ,, and unbolt master cylinder and pull away enough to see if any fluuid between the two.

 

[Yeller]

You can also look from inside vehicle the back of the hydtoboost for any fluid ay the input pushrod ,, and unbolt master cylinder and pull away enough to see if any fluuid between the two.

This won't introduce air unless it is leaking enough to be more than obvious, like a stream of fluid running out while it is running.

The overflow from the reservoir is from compressed air taking up space in the fluid that is compressed while it is running. stop the engine the air expands and pushes the fluid out of the top of the reservoir. I've used a couple of hundred saginaw and CBR pumps to run hydraulics for either full hydraulic steering and/or steering boxes and/or hydroboost for decades. I can attest you can bleed air for weeks and often still do this until you run it and work the steering for sometimes an hour or more. So I don't even worry about some air in the system, run it, make sure the reservoir is full with the engine running and run it. When all of the air is out of the system the reservoir will be the same level whether the engine running or not.

 

[RonJones]

This won't introduce air unless it is leaking enough to be more than obvious, like a stream of fluid running out while it is running.

The overflow from the reservoir is from compressed air taking up space in the fluid that is compressed while it is running. stop the engine the air expands and pushes the fluid out of the top of the reservoir. I've used a couple of hundred saginaw and CBR pumps to run hydraulics for either full hydraulic steering and/or steering boxes and/or hydroboost for decades. I can attest you can bleed air for weeks and often still do this until you run it and work the steering for sometimes an hour or more. So I don't even worry about some air in the system, run it, make sure the reservoir is full with the engine running and run it. When all of the air is out of the system the reservoir will be the same level whether the engine running or not.

There’s no evidence of leaking; uV dye in the fluid, and a uV light shows nothing. I’m not thinking I’m at the position to drive it, though.. I added fluid to the bottom of the neck, ran it for less than a minute, and moved the steering wheel 10 deg left and right four times while jacked up. Popped the cap, and the bubble-laden fluid was pouring out. I also discovered a chunk of what I guess is some kind of burp suppressor is missing from the cap. I suspect that can gum up the works. It looks like I need to vacuum out the fluid and hope I can catch
that hopefully single piece. I have a filter in the install, but unless it’s broken up into small pieces, I think it’s too big to get there.




.

 

[Yeller]

that is probably what started the entire deal. New one on me....

 

[RonJones]

that is probably what started the entire deal. New one on me....

Yeah, I’m special that way. The filter is on the return line, so for it to get there it would have go through a bunch of small holes. I’ve drained down to about half the pump casting, and not in sight. After that, I can’t see around the pump. If I’m lucky?, I can pull the pump and find it in the reservoir, otherwise iIt’s looking like I’m going to need to do a detailed disassembly and flush of everything.

 

[nvrstuk]

That sucks (bad pun).

If you didn't have the little pc of flexible in there somewhere the easiest way to get rid of that many bubbles is the way I learned from Master Pwr Brakes and another place. I did a tech write up I think. If not it is in my build thread with the 14 bolt install.

It works so slick and easy you won't believe it works.

You need a calder coupling or some way to attach a pc of PVC or something to your reservoir, then follow the simple steps.... if you can't find my detailed instructions then I will look later if you remind me. Works perfect, several guys have emailed me after trying it.

 

[RonJones]

That sucks (bad pun).

If you didn't have the little pc of flexible in there somewhere the easiest way to get rid of that many bubbles is the way I learned from Master Pwr Brakes and another place. I did a tech write up I think. If not it is in my build thread with the 14 bolt install.

It works so slick and easy you won't believe it works.

You need a calder coupling or some way to attach a pc of PVC or something to your reservoir, then follow the simple steps.... if you can't find my detailed instructions then I will look later if you remind me. Works perfect, several guys have emailed me after trying it.

Actually, I thought it was a good pun! I have seen that write up - I think I’ll try the vacuum method first, as I can do that solo with a 10 foot pvc hose and my MityVac. I have a crappy cap now that I can drill out and put a bulkhead 3/8” barb in.

 

[nvrstuk]

When you have a hydr ram the mighty vac won't help at all because you literally can't suck the air out of a dead headed ram in a cyl.

 

[RonJones]

When you have a hydr ram the mighty vac won't help at all because you literally can't suck the air out of a dead headed ram in a cyl.

Makes sense!

 

[RonJones]

I founded it! It looks like the piece of rubbery plastic didn’t go anywhere, so unlikely to be a problem, I’m thinking.