Hi guys - It's that time of year here in NY where you get the hot rod ready again.
67 Chevelle SS396 w/ remote power steering res.
I've had another P/S pressure line fail at the crimp closest to the steering box. The first one was a GM NOS piece, the second was from a local parts store.
When installing, I made sure there was flex in the line to accomodate engine twist in the frame (solid motor mounts).
I'm also using ATF, which from what I've read is a no-no. I was about 5 months between replacing the line and having the failure repeat. Some of the posts I've searched mention that ATF is tough on the rubber parts.

My question is - Should I flush the pump/gearbox, replace the line, and refill with GM P/S fluid, or just make up a steel braided line? Would the use of ATF have led to the pressure line failure?

Verify flush procedure:
1. Replace pressure line, fill with fluid, turn lock/lock about 20 turns to bleed air.
2. Pull return line from pump and plug off pump - I'm pretty sure it is a barbed end on the pump, so just a piece of hose with a bolt to plug the open end?
3. Keep reservoir filled during flush
4. Start car and have pump send fresh GM fluid through gear box - I figure 2 qts to do the flush.
5. Reconnect return line, top of reservoir.

Thanks for the help. It feels good to be working on the car again.

Two ps pressure hose failures?

First Guess: Hose is being over-pressured. Does the pressure relief in the pump work?

Second Guess: Hose is being used over it's thermal rating. How hot is your fluid?

If I read your posting correctly, the OEM hose could have been on the car for the last 40 years. The second, aftermarket hose, was just on the car for a short time. Most likely obtaining another OEM hose is literally out of the question. I would suggest that you try another source for your replacement, aftermarket hose.

I was the supervisor at Saginaw Steering Gear Division, GMC for the power steering hose group during the 1970s and early 1980s. We really did make a very high quality power steering hose. Unfortunately, Saginaw is not in the business of manufacturing low volume, service hose assemblies. So you have to rely upon people in the aftermarket business.

I would drain most of the fluid out of the system by disconnecting the return line hose from the reservoir spout. Direct the hose to a pail and plug the spout on the reservoir. Then "push" as much of the rest of the fluid out of the system by jacking up the front tires and rotating your steering wheel full lock to full lock.

Now reconnect the return line hose at the reservoir and add power steering fluid. Now "push" fluid through the system by rotating the steering wheel. Refill as the fluid level drops in the reservoir.

Drain most of the fluid by disconnecting the return line again and "push" the fluid out into the pail.

Reconnect the hose and refill again. Now you want as much of a complete refill as possible before starting your engine. You want to get as much air out of the system first.

Jim

Two ps pressure hose failures?

First Guess: Hose is being over-pressured. Does the pressure relief in the pump work?

Second Guess: Hose is being used over it's thermal rating. How hot is your fluid?

1. Not sure if pressure relief is working - Can you suggest how to check?

2. Unable to check P/S fluid temp with out mounting a sensor

The more I think about it, I can recall threading the fitting into the gearbox being a PIA, as there was just enough hose slack to get the fitting to thread. Maybe there wasn't enough slack in the hose to accomodate engine twist.

The more I think about it, I can recall threading the fitting into the gearbox being a PIA, as there was just enough hose slack to get the fitting to thread. Maybe there wasn't enough slack in the hose to accomodate engine twist.
Go there first.

I have used ATF in my system for the last 15 years, never had any kind of leak from the hose itself.

I did have a leak when the hose and tube assembly was accidently installed with the tubing touching the header, burnt right through the tubing.

Lucky the whole car didn't burn up, quite a smoke show.

Just to follow up with some additional info that came back to memory -

I had 2 pressure hose failures int the same spot. I was running rubber engine mounts at the time, and had a very wicked engine vibration at idle. It would shake in the mounts so bad the shifter would rattle inside the console. I've since changed to solid motor mounts and the engine shake at idle has quelled.

I've replaced the P/S pressure hose, and flushed the system to use GM P/S fluid. I guess time will tell if this was the cause.

I fired the car up and drove it for about 10 miles Saturday. After sitting in the driveway for 2 hours, there was a P/S fluid puddle under the car the size of a quarter - The 3rd new hose is weeping from the crimp. Same spot as the previous two hose. So I'm guessing I've got an inactive pressure relief valve in the pump(?).
I'm planning to pull the pressure line fitting and flow control valve out of the pump tonight, but I'm not 100% sure what I'm looking for. From the research I've done on the internet, that flow control valve looks like a spring biased spool of some sort. Is there anything in particular that I should be inspecting for other than dirt/metal/contaminants that might be holding this thing open?
Could this be a gearbox problem I'm having? The steering is silky smooth when driving: no grinding, no noise, etc.
What is the "name" of this style pump that was used on the 66-68 BB Chevelles? Edit: Found a previous post by JimL. Saginaw P-pump.

Any help or direction would be greatly appreciated.

interesting

The more I think about it, I can recall threading the fitting into the gearbox being a PIA, as there was just enough hose slack to get the fitting to thread. Maybe there wasn't enough slack in the hose to accomodate engine twist.

After sitting in the driveway for 2 hours, there was a P/S fluid puddle under the car the size of a quarter - The 3rd new hose is weeping from the crimp.
Did you ever get the hose length issue sorted out? The hose MUST have slack in it; hose will fail almost immediately if they're installed with too little slack--or with a twist in the hose material.

Did you ever get the hose length issue sorted out? The hose MUST have slack in it; hose will fail almost immediately if they're installed with too little slack--or with a twist in the hose material.

I originally mentioned that going off just memory. There is slack in the hose. As far as the twisting goes, I'm at the mercy of the orientation when the hard lines were crimped to the hose, but things did line up pretty well.

I pulled the pressure union and flow control valve out tonight. Nothing obvious stuck out, just some very fine black "grit" - Maybe the vane tips wearing at the pump housing(?).
I wasn't able to see much of the PRV. The filter screen ahead of it was in the way. There wasn't much contamination on the screen, just more of the mentioned black stuff. It looks like the shaft at the nut is peened over. I didn't want to file the peen off and find out that the filter screen would fall out and not be able to be replaced without hearing from somone to proceed. Even then, I'd need the PRV spring rate to determine if it is correct or not.
I'll try to locate a flow control valve from another late 60's pump to give that a shot.

When I put in a seal kit this past winter, I used my old presure line. Thought about puting in a new one with the cadium gold end, guess I'll stick with the old o ne with the plating worn off. Did replace the return line. A friend who does a lot of work on hydrolic lines gave me some 3/8" hose he had. Seems to be working fine. No leaks anywhere. Mine was leaking from the input shaft seal. I think everone uses the same supplier as far as Inline Tube, The Right Stuff, Ground Up, and Classic Muscle who presssure line is suppose to be correct at $40.

Just a follow up -
I couldn't find anything blatantly wrong with my pump, so I put it back together. I ended up making a pressure hose with the blue covered, braided hose and fitting from Earl's. No more leaks. The only problem I have now, is that I'm having to run the rubber return hose. The return hose I made with the braided stuff wasn't flexible enough to go over the barb on the pump return fitting.

The re pop stuff is questionable at best. The pressure line on mine hasn't developed a leak to date. The smaller return line from box to pump has began bleeding, forming sweat beads pretty much its entire length. I run the GM fluid and the car has a couple test trips to the end of the street and back. While sweeping the floor and noticed a stain, to say the least that hose is a POS. It amazes me that something so simple some suppliers manage to screw up.....:sad:

I guess I'll dig into the pile of receipts to see who's master piece this is so I can send them a thank you note.

Never had any problems with atf, i've used it for 20 years in the p/s

I'm having to run the rubber return hose.

The smaller return line from box to pump has began bleeding, forming sweat beads pretty much its entire length.
Power steering return hose is a specialty product, it is NOT just generic rubber fuel hose.

The PS hose has to cope with a different set of chemicals than fuel hose; and fuel hose doesn't have to cope with the heat of PS fluid. It does not have to deal with much in the way of pressure, though.

As long as the hose you're using is safe with the PS fluid/ATF, and safe at the temperature range it'll be used at, you "should" be fine.

Perhaps the Damned Communists are supplying rubber hose that doesn't meet specs like they supply poisoned food and contaminated toys.