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Steering gear loses all fluid out input shaft

CyberSniper

CyberSniper

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So, I'm kind of stumped.

Vehicle is a 1978 GMC motorhome, but uses the same steering gear in 73-83ish Chevy 3/4 ton pickups.

It's kind of an odd vehicle, hydraulic wipers driven off the return line of the steering gear, etc.

It used to leak a little fluid out the input shaft seal. Then during the summer when I was putting a motor in it the leak got much worse.

I have since bypassed the hydraulic wipers (it's getting converted to electric). So literally the pressure line goes to the pressure port on the steering gear and then there is a brand new return line to the reservoir on the pump.

It will run 2-3 minutes (warming up the motor as I still need to break it in) then it will spontaneously decide to pump all of the fluid out of the reservoir... via the input shaft seal. When it goes, it goes fast. Like the whole pint in 30 seconds or less. And it makes god awful racket when it does it (like when a pump goes to bypass).

Once it starts pumping all the fluid out via the input shaft seal I can stop the motor, refill the reservoir, start it up, and it instantly pumps all of the fluid out the input shaft seal.

If I wait a day or so it goes back to the point where it'll run for a couple minutes before it pumps all the fluid out the input shaft seal.

Do you think maybe there is shit inside of the steering gear that wallows around in there and then blocks the return?



Timeline:
Motor blows in March, but it ran at that point and the input shaft seal leaked a tiny bit. Like never drips on the driveway but the steering gear is oily.
Get motorhome towed to my house in May.
I pull the motorhome's sadness out in July.
I put the motorhome's new Cadillac 500 in September.
I started it maybe a week and a half ago and discover all sorts of problems. One being it pisses fluid out of the input shaft.
Replace steering gear input shaft seal.
Pisses fluid after 2 minutes.
Bypass wipers because I think the valve may be bad, but still use the old plumbing.
Still pisses fluid after 2 minutes.
Bypass all of the return line plumbing and get new 5/8-18 threaded 3/8 inverted flare to 6an plumbing.
Still pisses fluid after 2 minutes.
 
Well since no one else has said anything, I am going to venture that maybe the input shaft was weak before, and possibly a small piece of dirt or trash has either hung the pressure valve in the pump, or caused a restriction in the valves just below the input shaft of the box, which is more that the steering input can handle.
I don't remember if there is a bushing which holds the input shaft, so I don't know if you can replace more parts, or if you need to look at a rebuilt unit.
 
Just get another steering box.
Scrapyard or Rockauto or eBay.
It isn't worth messing with anymore.

There is no timer in there or anything to explain it pissing fluid on a schedule.
Your steering box seals are worn out.
The fluid is probably warming up enough to push the already jacked seal out and leak after 60 seconds.

I found Napa has steering boxes for about $179 last time i checked.
My 76 k5 had a leaker but that crazy cook at Arrowhead bought the truck before i got around to swapping a rebuilt box in it.

Edit:
Hey, is that one of those spaceship looking GMC motorhomes?
A roomate had one.
Has gigantic windshield wipers.
You might want to keep that hydraulic wiper system.
Those blades are gonna be hard to push with an electric motor.
 
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I just did a warranty replacement for my Napa Steering box. After I put the new one in, night and day difference in tightness. I'd go for a new steering box from them. Maybe even a new pump if you're bored.
 
I'm kind of torn about replacing it. It is really tight (no slop) and the pitman arm has no play and doesn't leak. I have only had one remanufactured steering gear that didn't have problems, ever.

I'm wondering if the steering gear is just full of crap that blocks off the return port. Not much else makes sense. I'm going to play with it some more today when I feel like having melting snow on me.

It's the spaceship style motorhome. I have NOS wiper assembly out of a Pontiac Transport that I'm going to use. It's a PITA to replace but it's better than the hokey hydraulic setup. It was probably cool in the 70s, but by the 90s electric things were better.
 
Cool ride. I’ve secretly kept my open for one. I don’t know enough about them to be serious. I assumed they would have all kinds of goofey problems.
 
My old roomate had one.
That is how i knew it looked like a spaceship.
He removed one axle from the rear.
Never could figure out why.
Suppose he just liked it that way.
We put an Oldsmobile 455 in his.
Or maybe it already had one and it was worn out.
Just remember helping work on that thing.
They are cool.
 
Steering gear was full of crap, I think it was the inside of the low pressure hose falling apart. Ended up running a few more quarts through it to clean it and the reservoir out.

The leak ended up being a junk seal from O'Reilly. I got a new seal kit from Autozone (appears to be National brand) and it works fine. The O'Reilly seal had the same dimensions but was of far inferior design (no soft seal goo around the outside which turns out where most of the fluid was leaking past) and there was only one lip on the seal instead of two.

Now I have the disdain of dealing with bleeding the brakes. If I could get the air out of the brakes I could drive it.
 
Make a vacuum bleeder so you can bleed them alone ...
All you need is a glass or thick plastic jar with an air tight lid,and a few hunks of 3/16" brake line,and a long enough length of hose to reach all the bleeders and to the engine,which you'll use as your source of vacuum ..

This photo below might help give a better idea of how it's constructed..
The one pictured ,uses a different method of attaching the hoses to the jar,I just drilled holes in the jar lid for the two hunks of brake tubing ,rather than buy expensive fittings that you don't need--I soldered the tubes to the metal lid,but I also used J-B Weld or RTV to seal around the tubes where they poke thru the lid..

One tube needs to go almost to the bottom of the jar--that one you'll connect to the bleeder screw using clear vinyl hose--the other tube only needs to go just past the lid,that one you'll connect to your engine,to a manifold vacuum source,and I use a pair of vise grips on that hose as an on-off switch--then all you have to do is start the engine,connect the hose to the bleeder,open the bleeder,and release the vice grips,and it'll suck out all the air in seconds..

I have used my shop vac as the vacuum source too,it has worked a few times,but it lacked enough "pull" to do a good job sucking the air and fluid out--the engine provides plenty of suction..

In a bind you can just use the hose directly to the bleeder from the engine,and the vise-grips as a shutoff switch..if some brake fluid gets sucks in the engine it'll just burn off and make white smoke,there isn't enough fluid in the master cylinder to do it any real harm or hydro-lock it..brake bleeder.jpg
 
diesel4me said:
Make a vacuum bleeder so you can bleed them alone ...
All you need is a glass or thick plastic jar with an air tight lid,and a few hunks of 3/16" brake line,and a long enough length of hose to reach all the bleeders and to the engine,which you'll use as your source of vacuum ..

This photo below might help give a better idea of how it's constructed..
The one pictured ,uses a different method of attaching the hoses to the jar,I just drilled holes in the jar lid for the two hunks of brake tubing ,rather than buy expensive fittings that you don't need--I soldered the tubes to the metal lid,but I also used J-B Weld or RTV to seal around the tubes where they poke thru the lid..

One tube needs to go almost to the bottom of the jar--that one you'll connect to the bleeder screw using clear vinyl hose--the other tube only needs to go just past the lid,that one you'll connect to your engine,to a manifold vacuum source,and I use a pair of vise grips on that hose as an on-off switch--then all you have to do is start the engine,connect the hose to the bleeder,open the bleeder,and release the vice grips,and it'll suck out all the air in seconds..

I have used my shop vac as the vacuum source too,it has worked a few times,but it lacked enough "pull" to do a good job sucking the air and fluid out--the engine provides plenty of suction..

In a bind you can just use the hose directly to the bleeder from the engine,and the vise-grips as a shutoff switch..if some brake fluid gets sucks in the engine it'll just burn off and make white smoke,there isn't enough fluid in the master cylinder to do it any real harm or hydro-lock it..View attachment 286833
Click to expand...
That is the nicest execution of a DIY vacuum bleeder i have ever seen.
 
It beats trying to pump the pedal alone ,then jam a board between the brake pedal and seat,like I had to do last Saturday when I replaced a rear wheel cylinder in my diesel pickup..no vacuum on diesels!..:doah:

I was able to get the system bled that way,at least enough to drive it OK,it probably could use a better bleeding still though..

The vacuum bleeder worked great to get a stubborn hydraulic clutch bled out one day at my friends shop--despite me pumping the clutch pedal up on the lift while he bled the slave cylinder,we just couldn't seem to get all the air out...spent an hour screwing around,took 2 minutes with the vacuum bleeder..

I was tempted to post about your P/S gear leak,it sounded to me like there was a blockage in the gear or system and too much pressure was building up--but seeing the windshield wipers run off the P/S pump and I'm not familiar with that setup,I figured I'd best not..
I was thinking "deleting" the wipers from the system may have caused the issue somehow..
 
diesel4me said:
It beats trying to pump the pedal alone ,then jam a board between the brake pedal and seat,like I had to do last Saturday when I replaced a rear wheel cylinder in my diesel pickup..no vacuum on diesels!..:doah:

I was able to get the system bled that way,at least enough to drive it OK,it probably could use a better bleeding still though..

The vacuum bleeder worked great to get a stubborn hydraulic clutch bled out one day at my friends shop--despite me pumping the clutch pedal up on the lift while he bled the slave cylinder,we just couldn't seem to get all the air out...spent an hour screwing around,took 2 minutes with the vacuum bleeder..

I was tempted to post about your P/S gear leak,it sounded to me like there was a blockage in the gear or system and too much pressure was building up--but seeing the windshield wipers run off the P/S pump and I'm not familiar with that setup,I figured I'd best not..
I was thinking "deleting" the wipers from the system may have caused the issue somehow..
Click to expand...

When i did my 3" ORD lift on the m1009, I also replaced the front rubber brake lines and rear rubber brake line with the longer version ORD sells.

It had a lot of trouble bleeding the system.
Also being diesel, i had to use a hand vaccum pump.
To complicate matters, my proportioning valve was sticking.

What finally did it was to carefully bench bleed the master cylinder.
Remove and clean out the prop valve.
Bleed fluid from the master cylinder to the prop valve.
Then a whole lot of bleeding at each wheel.
Had to flick the new brake lines, particularly that rear line, as a stubborn air bubble just wouldn't budge.
Finally got it after almost a whole day.

I think next time, i might try and flush out the new brake lines with brake fluid and a syringe first.

Been rock solid brakes ever since though.
 
I've been relatively lucky using the gravity bleeding procedure also,it works best when you've installed all new lines and hoses,calipers,etc..
I just open the furthest bleeder from the master cylinder (after bench bleeding it first),then go have a coffee or do something else for awhile--eventually you'll see fluid dripping out of the bleeder..usually it works pretty good,but I've had issues like yours too,where it seems no amount of bleeding helped any..

The PV is often a pain,I couldn't get one to shut off the brake warning light no matter what I did,despite the brakes being fully bled and working perfectly--so I pulled the tan wire off the PV under the hood so I could get an inspection sticker,and not have the light on constantly..it still works when you apply the E-brake that way too,they check for that also!..
 
The original old seal on the steering gear was definitely tired. It was hard and dry. O'Reilly seal was a POS. Autozone one is nice. Still need to pick up the spare I bought...

The brakes have been a PITA on this thing. I've replaced the master cylinder twice on it in the last 2 years. Other people have worked on it (its home is in Wisconsin, it is my in-laws, I had them tow it to my house because I was tired of going to Wisconsin to work on it) and some asshat would leave the cover popped and when it rains the water drips on the master cylinder and quickly destroys the piston and bore. He's found nothing but bad mechanics. The guy that did the head work in Janesville was solid mediocre and the guy in Janesville that built the exhaust was great... other than that... nothing but problems. One guy even left a pair of pliers in the lifter valley.

There are a lot of high spots in the brake lines (they've all been replaced by a hack mechanic in Stoughton, WI). The fronts are fairly easy to bleed. The rears are a PITA. I've run 7 quarts through it so far in the last month to get it so the pedal doesn't bottom out. It will gravity bleed no problem, but it leaves air in it. I have tried pressure bleeding (made a reservoir lid I can put compressed air to) and vacuum bleeding (using a HF vacuum pump and a setup way less ingenious than @diesel4me). For whatever reason, you need violent stabs of the pedal to make the air move. It's enough where the boss lady's legs get tired.
 
https://www.speedwaymotors.com/Speedway-Proportioning-Valve-Bleeder-Tool,296895.htmlThere is a special tool to aid bleeding the brakes on a GM vehicle equipped with a proportioning valve.
It is not normally needed.
But if you have a large amount of air, it may be useful.

The proportioning valve may be sliding over and stopping flow to the rear wheel cylinders.
That is what it is designed to do when it detects a pressure differential between front and rear systems.
It could be doing just that.
Symptoms would be;
Little to no fluid or air coming out during bleeding.
Brake warning light on or comes on momentarily during bleeding.

The tool is put in place of the brake warning light switch and holds the prop valve cylinder centered.

Your RV must have 13 miles of rear brakeline.
That is a lot of air to push using that tiny rear master cylinder piston volume.

I found the tool.
Speedway motors makes a brake prop valve bleeder tool that replaces your warning light switch and holds the p valve piston centered for bleeding.
 
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The combination valve is pretty easy to deal with. You just can't have the bleeder open when you press the pedal and you have to close the bleeder before you run out of pedal. It can be a PITA to reset sometimes though. I forget what master cylinder I've been buying but it moves a decent amount of fluid... 7 pumps and the reservoir is empty.
 
Sometimes leaving the engine running while bleeding brakes on a power brake system helps,the additional pressure from the booster helps force the fluid out of the bleeder better..
I imagine a motor home probably has hydroboost brakes,most of them do..
Having the brake lines high up shouldn't matter as long as they aren't higher up than the master cylinder is..if a "hack" replaced them,I'd be sure no kinks are in the tubing and he didn't use compression fittings to join them..if enough water got in the master cylinder in the past to ruin it,the steel lines may now have rust growing in them too..
 
So I built a vacuum bleeder similar to what @diesel4me described. It worked better than a vacuum pump, but I still had air in the lines.

I fixed the fuel leak, or at least masked it, I think. I need to go over the whole fuel system again when it's not 20 and windy. I had it all fixed last year but some hack has been under it.

I had my Dad come to my house for his birthday and help me bleed the brakes. One time I made my Dad hold the brake pedal down *hard* for two minutes because I managed to drop all of my 10mm wrenches just out of reach and I was low on fluid and didn't trust that I had the bleeder tight enough. The pedal slowly went to the floor. Tried it again... was fine. We had all of the air out of the back brakes! No sponginess.

The pedal slowly went to the floor again while we were bleeding the front brakes (for shits and giggles, after running 12 quarts through the brake system in the last month why not another one?).

I had my Dad stand on the brake pedal while I went and found the leak. There was a union right by the T to split the lines to go each side under the motorhome right by where the fuel leak was. It was painfully obvious where it was when the fuel pump wasn't spraying gas all over the union. One side of the union was tight... the other side was finger tight. This thing had been down the expressway at 70mph with finger tight brake lines! The auto repair shop that did such a fine shop in Stoughton, WI has since closed up.

I hope to move it from in front of my garage today. It's been sitting there since May.
 
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