HydroBoost / Power Steering setup sucking air

[John_parkeriv]

So I've just finished installing my HB/PS setup on my 351w. AN lines were an absolute nightmare to put together, but they all seem solid and not leaking. I pour steering fluid in the Saginaw pump and fire the truck up. Sounds fine, the I turn the wheel and it screeches like a banshee. Try to use the brakes and it screeches too.

"Oh," I thought, "New PS parts, probably need to bleed the system out." Jacked up the front of the bronco, held the brakes down, and turned the wheel lock to lock about 5 times. Fluid and bubbles spewed out everytime I made it to full lock. Refilled the reservoirs, and redid the bleeding about 25 LTL's. No matter how much I turn it, and how much fluid I add; it just keeps on bubbling.

At this point, I'm suspecting an air leak somewhere as all the fittings still seem leak free. I've seen guys test the new remote reservoirs with a rad pressure tester, but how would you test a Saginaw?

What's the best way to ID the leak with a canned ham pump? Also, just to be safe, the feed line from the pump goes to the passenger side of the HB (the side with the gas canister), right?

Thanks!

 

[Madgyver]

Did you bleed it properly?
I pull off pitman arm. fill reservoir with ps fluid. spin ps pump pulley by hand, turn steering left and then right slowly 5 times, pump brakes slowly 3 times letting pedal return each time, check fluid, fill if needed.
DO THIS CYCLE 50 TIMES. No other way around it. take your time. because if the pump fails it will throw debris throughout the system and you will need to flush it out and start over after you replace the pump. do not run pump with engine before bleeding cycles.
if fluid is bubbling you will need to step away and let it settle for 30+ minutes before going at it again.
I've been doing this for the last couple of days.

 

[John_parkeriv]

Did you bleed it properly?
I pull off pitman arm. fill reservoir with ps fluid. spin ps pump pulley by hand, turn steering left and then right slowly 5 times, pump brakes slowly 3 times letting pedal return each time, check fluid, fill if needed.
DO THIS CYCLE 50 TIMES. No other way around it. take your time. because if the pump fails it will throw debris throughout the system and you will need to flush it out and start over after you replace the pump. do not run pump with engine before bleeding cycles.

How bad is it if I've already run it before bleeding? Does it just have to start over? I've only run it for 30 seconds or so at a time so I don't burn up the pump

 

[Yeller]

It’s usually not a problem. Mad is correct, and sometimes that still isn’t enough. Once think you have all of the air out start it, fill the reservoir to approximately full on the stick. Just let it sit and idle until the fluid is clear of bubbles and isn’t frothy. Then and only then turn the wheel 1/2 turn check the fluid, do all of of this with the engine running. Turn it to lock, check the fluid if it is still quiet slowly turn it the other direction stopping to check the fluid. Also do this with the tires jacked up off the ground. Once you can cycle the steering lock to lock 10 times with the engine running and no bubbles or frothing fluid then pump the brakes and be ready to let the froth settle again. After you’ve done all of this and the fluid is clear you can shut the engine down this will probably take 45 minutes to an hour, you may need a fan in front of the truck to keep it cool. When you shut the engine off if it pukes you get to start over so be patient.

 

[Madgyver]

Day 3 now, Into the evening 77* here in Honolulu but windy and still outside trying to get all the air out of my power steering/hydroboost system. I thought I'd have it driving tonight but I'm not rushing it. I'll hit it tomorrow again. probably about 40 cycles now and still see air bubbles rising up in reservoir when I finger spin the power steering pump. It is a GM type 2 pump.

 

[nvrstuk]

Worst "simple" job on a Bronco is cracking open the power steering system. lol

Add a hyd ram and unless you crack the fittings on the ram to bleed it AT the ram you can easily double the time.

I learned a trick that works and it has cut my time 4 fold or sometimes an entire day (or two). The key for all of us is to get the air moved out of the pockets in the system so the bubbles will get out the reservoir w/o damage to the pump. Release the trapped air!

Go through all the steps w/o starting but when you do start the engine you need a large reservoir because physics says air compresses and liquids don't.

So when you start the engine the reservoir level drops severely and often it drops low enough (because the air is compressing and therefore taking up less volume) that you will introduce more air into the system compounding the bleeding of the system. Even if you fill the reservoir to the very top it still does this- often.

What I learned from a Nat' Brake supplier (Master Pwr Brakes) is this: they don't do 1/10th of what we all do to bleed the system. They make an extension for the vehicles reservoir and fill it up. Start the rig and the air gets compressed, moves thru the system to the reservoir so the bubbles can escape and because the reservoir is so large you never introduce any more air. Boom- done.

I tried this and it works. I use a caulder coupler around my large PSC reservoir and a pc of 3" PVC pipe that is appr 15" long. No leaks.

I fill the PVC pipe with ps fluid, go thru my left turn, right turn back and forth a couple dozen times with the wheels of course off the ground. Start the rig and with someone there with a LARGE opening on a can of ps fluid (so it will pour fast) and then start the engine. The fluid will probably drop a foot- have your buddy FILL IT AS IT DROPS.

Let the engine run for 30 seconds w/o input. Shut it off for 10 min or until bubbles quit surfacing. Do this until no more bubbles. Then with the engine running go l to r without stalling on the full turn bump stops on either side- important. No more bubbles you are done. Should take 30 min.

Syphon off the extra qt of fluid out of the PVC pipe extension (clean fuel hose or turkey baster) so when you disconnect the caulder coupler you won't spill any fluid.

Done w/o pwr strg fluid burped all over your engine.

Shops can't afford to have their customers cars sitting and waiting for bubbles to bleed out for days on end. MP Brakes told me years ago they just start out by starting the engine and pouring fluid in. I still introduce some of the "basic steps" that I've done and others mentioned on this list since it still seems "right". Maybe because I've been doing it that way since HS.

 

[4x4man514]

man i didnt know so much was involved. im subscribing cause hopefully ill have this to do soon.

what do yall do if your breaking in a new engine at the same time?

 

[ransil]

return line into a bucket always worked for me, this is usually after trying everything else for 3 hours trying not to make a mess, its always a mess.

 

[Madgyver]

Thanks Brian for that tip. I see myself getting a plumbing no-hub coupling so I can attach it to the top of my reservoir to a piece of cpvc tube. I always find it overflowing while doing the cycling.. PS level moves a lot.

 

[nvrstuk]

Yup, that's exactly what you want! It will push the air bubbles out to the reservoir w/o sucking in more air creating the viscious cycle.

Let me know how it works for ya-we've had great success.

 

[Yeller]

Its a PITA. I developed the engine running technique having to fix stuff competing, we had to be back up and ready to run in 45 minutes, no time to play with bleeding with the engine off. it is usually less messy too, the trick is keeping the pump in fluid, it's easier with 2 people, someone watching and pouring and someone operating.

 

[DirtDonk]

what do yall do if your breaking in a new engine at the same time?

You don't if it can be avoided at all!
You have one and only one chance at breaking in a new flat tappet cam and lifters. Failing that and you're possibly rebuilding an engine again for all the metal "dust" that just circulated inside the engine. There is usually no do-over without doing the whole thing over.
By that I mean that your power steering system plays second fiddle to the engine. Along with literally everything else other than the cam break-in.

You can burp air out of the water (not anti-freeze) in the cooling system without fret. Or you can leave the belt off of the water pump.
You can fill a power steering pump as the engine is running to keep it from self-destructing, but you should have had the reservoir full of fluid to begin with. Just like the radiator.
Or you can leave that belt off as well, since the P/S is not needed for engine break-in. And you can simply avoid turning the wheel until the engine has had it's first 20-30 minutes of high speed run time.
You can even fill an auto transmission as the engine is being run, because it's likely already attached and is going to be run with the engine no matter what. But it should also have already been filled mostly with fluid before it being pumped through the rest of the trans so that at least there is a healthy startup.

Basically I'm just saying what you probably already surmised. Nothing takes precedence over running that cam break-in.
If something is wrong, you shut it down. If you want to do that with the power steering, auto trans and anything else, you shut it down and then fill it up. Then re-start and immediately bring to 2,000-3,000 rpm again and keep it there.
Which means doing your best to make sure everything is going to cooperate when you first attempt to fire it up. As you would expect...

Good luck. Hopefully someone else has a more upbeat and less dire method.
Or if you have a roller cam it's all moot!

Paul

 

[Yeller]

If a new motor with a flat tappet cam I’ll either leave the power steering belt off if v belt or run the pump with a drill motor first to make sure it’s bled first.

 

[papy]

what Macgyver said. I think it was 4 days taking my time L R L R LR and so on

 

[Broncobowsher]

Don't hold the brakes when turning lock to lock. You are messing with the flow.

Now that you have foam in the lines. There is an easy, but somewhat time consuming way to fix it. Start the engine and shut off right away. Cranking the engine isn't enough speed for the power steering pump, has to run. But you want it shut off before it can fully cycle the fluid through the system. You put a slug of foam into the reservoir and wait for that to settle out. Add a touch of fluid. Repeat. Much like a little fluid on the floor looks like a huge amount, a little air in the system looks like a lot.

The air in the oil is compressed while running. When you turn it off, the pressure goes away and it expands back to normal. This expansion is what pushes the oil out. Getting the air out of the oil is the key. Doing so while preventing new air from getting in is difficult. I have even seen people rig up a vacuum fill system (much like they do for engine coolant), but with an already filled system you will need a good puke tank to avoid flooding the vacuum pump with power steering fluid. This was copied from how the plant fills a dry system. Works best on a dry system.

 

[Oldtimer]

So . . . How do manufactures fill a system on the assembly line, after various workers have connected mulitiple components (and not have fluid everywhere)?

You guy have almost talked me out of hydroboost.

 

[Broncobowsher]

So . . . How do manufactures fill a system on the assembly line, after various workers have connected mulitiple components (and not have fluid everywhere)?

Vacuum fill. Pull a vacuum on the whole system, no air at all inside. Just the void of a vacuum. Inject the oil, its all pre-engineered to know exactly how much goes in. Perfect fill. Also works on cooling systems. And the only way an A/C system will take a fill.

The bad part about a vacuum fill with used parts is the air bubbles deep in the system expand to nearly infinite size and push the fluid out of the system. You have to catch nearly all the oil in the system as the vacuum is applied.

 

[nvrstuk]

Honorio-- it's Sat night. I saw ya in your elf outfit (love it).

Ya running??

 

[Madgyver]

Honorio-- it's Sat night. I saw ya in your elf outfit (love it).

Ya running??

I was running. Pulled the heads off to check everything. Really wanted to check the valve cuts on top of pistons and generally look over everything as this Clevor was pieced together with my recipe years ago.

 

[ngsd]

Hey Mad, It is March now and was wondering if you have finished bleeding yet? I am doing the same right now and it is taking forever. Also have the type 2 GM pump.