creeve4

94 4Runner, V6, ~180k

My PS pump had been leaking slightly for about a year (I have always kept it filled, usually with a stop leak type fluid). About 2 months ago it got really low after one of the hoses disconnected. I reconnected the hose, drained the fluid, and filled it with Lucas brand PS stop leak fluid. Since then it has not leaked. Today, after driving on the highway for about 15 minutes, the power steering completely gave out when I slowed to get off the highway. About 30 seconds after getting off and having slowed down to 15mph, the power steering came back.

I know that the PS pump is the likely culprit, but want to get some opinions before I replace it. Could there be any other cause?

To summarize:
-PS pump has a history of leaking, but has not leaked since filling with Lucas brand stop leak fluid.
-Power steering completely gives out after driving at highway speeds, but immediately returns once I reduce my speed below 20mph.
-All hoses are connected and free of damage
-PS pump belt is properly tensioned
-PS pump is original with 180k miles on it

Side question: does anyone have a diagram showing which engine hoses go where? I want to verify that all of my hoses are connected to the correct place (even the FSM doesn't have this information).

scope103

I would say that's your problem.



The power steering pump is only to be filled with ATF. I don't have personal experience with this, but it seems the general opinion on this forum is that violating the manufacturers instructions is a common cause of destroying the power steering pump.

There are rebuild kits (seal sets), but if using the wrong fluid is the cause, you may be better off with a reman. RockAuto has them for as little as $53.

RJR

I lost the seals in mine before I realized it required ATF. A reman pump and the right fluid and all is good.

87blackbeauty

My pump gave out after being filled with good ole power steering fluid. Turns out your power steering pump is actually just an automatic transmission, and you should treat it as such. Mine's happy with ATF and shifts great!

But really, PS fluid killed one, as it was drained for some service (long time ago, don't remember) and was refilled with crap. New pump was put on after about 60,000 miles of no power steering and filled with ATF. No leaks, no issues.

Gevo

How yhick is this lucas oil? I hate stop leak type of product. Just masks the problem until it gets bigger. Also how did a hose come off? Maybe your pump is ok and the leak is from the hoses?

creeve4

Thank you all for the information.

I am going to go with a reman pump, but they do not include a reservoir. Is there any reason (bad seals, etc) that I would need a new reservoir?

The hose detached because the clip holding it on broke (it was the original clip).

Any suggestions for bleeding the power steering system?

RJR

I know I transferred the reservoir when I changed mine, but I don't remember the details. The instructions with the reman pump were pretty clear, and I had no problems. The whole job took about 2 hours, I think, and I'm not particularly fast. Make sure you break loose the bolt on the pulley before you loosen the belt. I also wound up removing the battery for more room, and that was key because it allowed me to get an impact wrench on the high pressure banjo bolt to break it loose. Without that it would have been easy to twist up the high pressure hose and damage it. New copper washers for the banjo bolt are a good idea. I didn't do that and had to work with that fitting a bit to keep it from leaking.

hyo

iTrader: (1)

the new pump should have all the necessary seals you would need.