79 FJ40 power steering troubleshoot (1 Viewer)

[crewzerdog]

Have a rebuilt OEM p/s pump and original steering box on a 79FJ40. Before my frameoff work of the last 14-16 months it worked great - after rebuilding the pump using the Toyota "kit" (basically it just replaces the various "O" rings) and reassembling everything including using a new high pressure p/s hose I get no power assist? I'm sure the reservoir is full of fluid and I've jacked up the truck and, per the factory manual, with engine running I've turned the wheel repeatedly to extreme left and right in hopes of bleeding air out of the system - heck, I've even driven the truck around the neighborhood - still no luck. I 've got a new p/s belt and the pump spins great - no leaks or bad noises.

I'm at a lost on what else to try or how else to check this short of unhooking the high pressure hose to be absolutely sure the pump is actually pumping (this has got to be potentially messy and dangerous if the psi is very high) besides - I just got the truck back from the paint shop - any other suggestions?
Thanks...

 

[Poser]

I would not unhook it completly, but I would loosen it to make sure you are getting fluid to the ps unit...back the nut off a 1/4 to a 1/2 turn and see if fluid comes out before starting the truck... if nothing, unhook the coil lead, and try turning it over on the starter with the pressure fitting loose at the gear(no more loose than before) and see if you get anything..

Good luck!

-Steve

 

[Pin_Head]

Make sure that the reservoir is full when it is running.

Check for fluid flow by disconnecting the return line and pumping it directly into the reservoir.

It is hard to diagnose pressure problems without a pressure gauge, but you can get some idea if the pump is developing pressure by plugging the high pressure outlet and turning it by hand.

If you have flow and the pump develops pressure, chances are that the internal teflon ring seal on the power piston in the box is bad. W/o a pressure cauge, you can't be sure that the pump develops enough pressure.

The good news is that the cruiser uses the same power piston and internals as the mini truck PS box.

 

[hammerhead]

Had a similar prob years ago and went to bed pissed off. Next morning the dang thing worked flawless. Must have been the beer. Actually never did figure it out. Maybe it just needed to burp. Hehehe

 

[crewzerdog]

Thanks guys - some good suggestions - I plan to try them all this weekend. The one item that I did not rebuild or touch in any manner was the p/s gear box (mounts to frame rail) -- assumed that since it worked fine before the frame off work it would work fine again -- basically didn't want to mess with it as it was 'tight' with no leaks-- may a bad assumption. Thanks again - if I find a solution I'll let know.
Tom
79FJ40 - almost finished restoration!