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A.b.s. bleeding fail

I drained out the tank and washed it out with gas.. so far it's working fine now.theres no way that mucus water seeped in around seals . Gonna buy a locking cap for it..
So now that that is fixed , back to the original problem.. the dragging problem went away almost completely for a short while. Few days.. tiny bit of dragging here and there but went away quick.
But now it's back to usual dragging most of the time.. sucks.
I started flushing out the power steering as guys directed me to.
It doesn't seem like much fluid comes out the return hose at a time ,more of just a drizzle.. but I ran a gallon of power steering fluid through it before it even considered looking like p/s fluid instead of oil.. still not clean by any means. Gonna keep flushing it till it is. And then put dex /Merc in the system..I'm not convinced by any means that the fluid if the problem.. just doing it cause it needs to be done..
I'm not going to pretend I understand how the hydro boost system works cuz I don't. I just know the power steering pump supplies pressurized fluid to the hydroboost and the steering gearbox. I'm going to assume there's some kind of valves inside them that basically tell them when to use the pressure and when not to.. I think if I understand right the fluid goes into the hydroboost at high pressure so when you push the pedal it helps the hydro boost push harder on the master cylinder so you don't have to push so hard on the pedal.
That led me to think of that what would happen if the pressure is not getting back out of the hydro boost and is keeping it from releasing the pressure therefore not letting the master cylinder release all the way. My only reason for this thinking is the fact that the problem is intermittent. The only thing that can go wrong with the master cylinder really is having air in it in which case you just wouldn't have very good breaks if I understand right..
And the fact that the steering is affected at time also leads me to think that the problem is somewhere in that system between the pump the hydroboost and the gearbox. .
My other reasoning is that sometimes when I push the pedal it goes halfway down before it ever gets pressure at all against my foot and even then it's not perfect pressure.
Other times the pedal is a good and hard and all the way up where it belongs.. as in from the time you start pushing it it's hard like it should be right from the top..
When it's good and hard, it swings back up to the top quickly when you take your foot off it. So hard that you hear it thump when it gets to the top. The other times when it goes halfway down before getting pressure it takes its dear sweet time coming back up.
A couple of you suggested connecting the two high pressure hoses on the hydroboost to each other , thereby bypassing the hydro boost. I want to try this, so my question there is when I unscrew the two hoses off of the hydroboost will the fittings just screw into each other or do I need some kind of adapter??
 
You'll need to make up an adapter. both of the pressure hoses on the HB are different size metric o-ring fittings, same as the gear box. what you'll need to do to bypass the HB is to disconnect the main pressure line at the HB that comes from the P/S pump and take that end down to the gear box connecting it to the port where the hose is that connects it to the HB. iirc that should work effectively eliminate the HB from the steering system.

I will caution you on this.... do a few test stops before trying to head down the road and can't stop the truck! without a working power booster you will basically have to put your foot through the floor to stop your rig!!
 
Ok I didn't something stupid. But learned something in the process.. I drained all the fluid out of the p/s pump and lines. And pumped brakes with engine off.. ended up getting extremely good pedal..nice and firm. And it slams back up fast and hard like it's supposed to.. started truck for a minute and it stayed that way. PERFECT... THEN I filled system with ATF.. it went right back to being squishy and going half way down before getting any pressure
 
with no power booster the pedal will get hard. the booster multiplies the force your foot gives it. if the pedal isn't returning properly there are two possibilities that come to my mind. 1. the piston in the MC is sticking. 2. the piston in the HB is sticking. since you already installed a Delco MC, I am leaning toward the HB sticking.

if you have the down time and tools to rebuild it, they do sell rebuild kits, but if the accumulator is not working, there is no point rebuilding. the way to check the accumulator is to run the truck and step on the pedal a couple of times. let it idle for a couple of seconds without pressing the pedal, then kill the engine. immediately press the brake pedal and you should still have anywhere between 1-3 "squishy" pedal presses before it gets rock hard. you also should hear a hiss or swoosh sound on the first press that will be less and less on the second and third press. that sound is the accumulator releasing it's stored pressure.

if you plan to attempt a rebuild on the HB. be sure you pump the pedal several times with the engine off to verify all pressure is gone in the HB. and DON'T mess with the accumulator during the rebuild. only focus on the piston and seals.
 
Here is one video on removing and rebuilding the HB. they all talk about them leaking, but take note of all the buildup crap that gets inside of them from the P/S system and from where the MC and HB mates together. any of this buildup can cause a sticking piston. if you do this, pay close attention to all of the bores and piston sides for scarring and lips that can cause sticking. you might need to use some emery cloth to hone areas.

 
I must have missed the spammer excitement.

the pedal not returning with fluid, I assume that is with the truck running and the P/S system in operation? sound to me like the HB is fubar. has internal bypassing seals.

think of it like a hydraulic cylinder that has a bad seal or scar on the ram or inner cylinder wall allowing pressurized fluid to get on the wrong side of the piston. this is what's called bypassing and can cause the slow return or in absolute worst case make it travel the wrong direction. fluid goes into the HB through the pressure line from the pump and has a valve inside that when you begin to press the pedal allows pressurized fluid to fill a chamber in front of the piston multiplying the force when you apply the brake. When you release the pedal the valve reverses and allows fluid to flow into the return chamber pushing the piston the other direction, in the HB, pushes the pedal up releasing the brake. there is not a lot of pressure in there to return the pedal up but if the seals are bad or the innards are scarred, the fluid pushes past the piston into the "apply the brake" chamber slowing the pedal down as it returns to the up position. Note: simply grabbing and pulling up on the pedal won't help because inside the HB, the linkage that connects the pedal to the internal piston is not connected but only sitting on the piston. pulling up only separates the two.

Hope my explanation doesn't have you going huh!
 
@dbrannon79 . No actually it makes a lot of sense the way you explained it. The hydroboost was replaced I believe twice after I started having problems with the truck. But the replacements were from AutoZone so no guarantee that they were any good.. so I'll start looking for another one.. rebuilding it isn't a option for me. For usual reasons. If something goes wrong or I screw something up. Or can't get answers to questions while in the process extremely quickly then I end up screwed because I don't have anything else to drive. Any no stores within walking distance for parts or really anything else for that matter.. so can't afford for truck to be down for more than the day I'm working on it.. it sucks 😞..
Couple questions though. 1) could this possibly effect the steering if what your saying is the problem.?
2) could that problem your describing be eradic ? What I mean is could it happen sometimes and other times it doesn't? Because sometimes the truck will run fine all day and then all of a sudden this issue starts happening. But at no time do I ever have good pedal.. it's always soft, the pedal travels halfway down before you get any resistance on it at all. And once you get the resistance it's still not firm. The only exception is when I said before when there was no fluid in the system at all. Then the pedal was really firm to push right at the top as soon as you start pushing it. And as I said before when you let off of it with the system empty of a fluid the pedal slams back up at you.
3) how much of a stream of fluid should you get out of the return line nipple on the hydroboost? Should it be a fair amount of fluid coming out like a squirt? or should It just drizzle out of the nipple? Even without touching the pedal or steering wheel fluid drizzles out of it.
And last question... Is there supposed to be a cooler on the system? Because there is one plumbed in down by the gearbox. But has fuel lines going to it. With o clamps . Almost looks like something somebody decided to put in. Actually never noticed it before today..
I had honestly thought I might have a collapsed hose. Not sure if the inside of them can collapse like a brake hose does.
 
@dbrannon79 yeah, evidently you did. The post was between your 9:27pm post of the video and @Stoney's 9:51pm 'Yeah, what he said' post.

The spammer post was all in Russian with several hyperlinks to other pages that were also in Russian. Thank you, @denata for your translation and I assume your reporting it to a Moderator for deletion and blocking of the member.
 
Having a continuous dribble from the return line when your were flushing without pressing the brake pedal would confirm the HB is bypassing. someone correct me if I am wrong that the return line would only squirt a stream to the return when pressing and releasing the brake pedal?

It's been a little while since I flushed mine, but I don't recall seeing any fluid coming out of the return until I pressed and released the brake. as far as the amount, it should be fast enough flowing out of the return that you only get maybe 5 brake presses before the pump is about to starve for fluid. but again I may be exaggerating it a little, I've slept since then LOL
 
Yeah, sounds like your HB is leaking internally intermittently - which would explain both your intermittent brake dragging and your intermittent stiff steering issues. Like we always say on here, "New doesn't always mean good, and rebuilt/remanufactured means beware." And "NEVER buy parts, especially electrical parts, from AutoZone!"



Also, the engine oil cooler should be up behind the grille in front of the A/C condenser with a pair of fairly large (like ½" OD) hoses from the oil filter area going to/from it. The P/S cooler (if equipped) is a lot smaller than the engine oil cooler and should have small steel lines (look like brake lines) running to/from it, if my Oldheimer's serves me right. Correct me if I'm wrong, somebody.
 
Yep it there is a P/S cooler it's a small bastard haha. my rig has one that's mounted to the drivers side behind the grille. I strapped a few computer fans to it for added cooling since it's in an area blocked off from wind by the grille. it helped some but eventually I would like to mount a tranny cooler in between the stack for the P/S to help it keep cool.

something to note. any "bypassing" in the P/S system creates heat. high pressure fluid pushing past a seal or valve that acts as a restriction will create heat and lots of it. I think you mentioned your steel lines get hot in a hurry when running. that fast heat build up can be another indication of a P/S system problem.
 
And if somebody previously did bypass/repurpose the P/S cooler, that extreme heat buildup in the system would eat seals up in the HB, steering box and especially the P/S pump! The deteriorating seals would definitely be the source of that black crud you were finding in the P/S fluid.
 
Thanks @Husker6.5 and @dbrannon79 . It's pouring rain today and next day or to but after it passes I'll get under it and get pics . The hoses going to the p/s cooler look like fuel line that was clamped onto the metal lines. Like if maybe the metal line failed and they just cut the broken piece out of it and used hose and clamps to repair it maybe..?
I have ATF in the system now instead of ps fluid.. I'm going to try and find a hydroboost but that may not be easy. Everything I find says reman on it. So it's taking a chance buying one.. what brand would y'all recommend? I'm not exactly financialy stable but if i can find a half decent price I'll figure out a way to make it happen. I want to replace all the hoses at the same time but there pretty cheap on rock auto. I doubt the brand makes much difference on them does it??
Once I get the hoses and hydroboost I'll try to flush out the ps pump and steering gear box best I can . They both MIGHT Still be under warranty. So if they are I'll replace them at same time.. but the warrantys would be from auto zone so not sure how good new ones would be..
Or should I just replace the hydroboost and hoses first and see what happens?
 
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