Ever had the plastic power steering dipstick melt?

[jhe.1973]

Hi Everyone,

Thursday upon starting my wrecker the steering wheel started spinning to the right by itself. When I grabbed it to turn back, it took off out of my hands spinning all the way to the left.

The pump was making noise as if it was out of fluid.

Shut it off popped the hood to look into the pump. The cap to the reservoir spun freely w/o the usual clicks.

This is what it looks like now on the right:



Everything from the rubber washer on down is nowhere to be seen.

I figure the missing parts have been ground up by the pump and circulated into the steering box, causing whatever valve that moves back and forth to stick in it's last position.

Any ideas? .... especially as to how the dipstick got hot enough to melt !!!

[KevinK7]

I don't recall if the original caps had (and don't know if yours 'had') the metal piece on it before-hand, but if so, it's possible (not sure why) it could have come loose, fell into the PS fluid resevoir, and got 'chopped up'. In the process, caused the wheel to 'turn on it's own', along with creating the heat that led to the 'meltDown'. Some of this makes sense (ie the metal falling in, causing the steering issue), but even I have a hard time imagining it got SO hot to melt the plastic, but hey, I'm just guessing here...

[Bob B.]

It sounds like you have a problem in the steering box, or the hoses are backwards. The pump was 'dead-heading', which will cause the fluid to get very hot very quickly. Unfortunately, this will also cook all the seals. Surprised it didn't toss the belt.

[70STOVEBOLT]

I've never seen a rubber washer like that on any GM p/s pump I've had. And all have had the metal piece with the spring.

[KQQL IT]

Is the ps pump also the hydraulic pump for the tow bed?

[MJN]

Can you show a picture of your pump and plumbing? The melted cap looks like the cap/dipstick on my '74 and the one with the rubber baffle is from later yet. I have a pump from a 1994 S-10 and it has the rubber baffle on it but all my older stuff doesn't.

[Palf70Step]

Have you ever looked at the cap before. Looks like someone left it off and on something hot, then just stuck it on to keep fluid from splashing.

[jhe.1973]

Hi Everyone,

Thanks for all the responses!

I haven't been able to get back here since posting cuz we had to make an unplanned trip for a few days.

The wrecker's winch is mechanically driven via chain from the PTO shaft.

Here is how the steering box looks now:



I had converted to power steering and moved the alternator to the passenger side of the engine in March of last year. I've used the truck several times since. Sooo, I know I have the hoses hooked up OK.

The first pump I used, and the steering box, came off of a C20 Squarebody that was to be scrapped. I think that truck was converted cuz a couple of the mounting brackets were machined with a cutting torch!

When I first used the truck with the 'new' steering, the single belt would squeal easily at the steering stops.

The pump I am now using came from a 70s junkyard El Camino with a double pulley. I had scouted the yard for a better reservoir cuz this is the initial one I had obtained:



Why both sides of the reservoir had been remodeled with a hammer is beyond me but beggars can't be choosers. I got the setup for free!

It only took me 5 or 6 years to get around to installing the setup.

One of my friends calls me "Speedy"!



While we were away from home I had the chance to get back to the junkyard and took photos of a bunch of El Camino pump setups to see how close they are to the exhaust manifold. This is one of the best examples of how the steering pump is canted towards the water pump:



I was leaning towards the idea that the mount I made has the reservoir too close to the exhaust and it picked up too much heat. In the right view below, the white arrow points to the bolt that the factory uses as a pivot point. I may try this location and see how it works. The left view shows how there are no bosses sticking out on the front of the manifold as I had to work around. It is because of these bosses that I could not use the El Camino brackets.



More to follow………………………………….

[jhe.1973]

Getting back to work on the truck on Saturday, I used a couple of magnets and fished this out of the reservoir:



The spring and clip aren’t even scratched. Now I was more convinced that the pump had digested bits of plastic and not anything metal.

Until I removed the pump and found that the pulley and shaft had way too much shake as if the inboard support was lost.

Oh great …. now what!!!

Today I pulled the reservoir off and found a round magnet loose inside (to the right of the pump body):



This close-up shows the bushing is thinner on the right side of the bore:



Plus this was in the bottom of the reservoir:



It looks like melted solder. It’s not magnetic nor is it plastic.

Hmmmm ………… time to check the overhaul manual.



This view shows a long bushing for the shaft. The only mention of it is in the text that I copied below the cutaway (bushing material pickup). Apparently the bushing is not a service part and that GM was aware that this bushing could deposit material on the shaft. Too tight a belt perhaps?.

So now after checking out more original examples of the El Camino pulley arrangement I am pretty sure that the pump only used one belt to drive the power steering and the other groove was for an accessory (air pump, AC compressor, whatever). I think by using two belts to drive the steering pump I loaded the shaft too much on one side creating the excess heat.

That’s my story and I’m sticking to it …………… (at least till I change my mind)

[Myself]

Usually this sort of thing happens when somebody slips a prybar down in there to get the belt "tight".......well.........that's too tight.