I recently bought a 88 4x4 pickup 5sp, 22RE, and it had sat around for a while. I replace the front brakes (pads only), brake lines to the rear were rusted through so they are new, new front passenger CV shaft (needed new outer boot). Anyway after putting it back together, we were bleeding the brakes, and they pump up with the truck not running, and bled fine, however when I started it, and tried to back it out of my garage, no brakes, not even if you pump them. We also noticed after that that if truck is off, and you pump, pedal does not stay hard, within a very short time, it is soft again. I figure it is the master cylinder right? Any help would be appreciated. Oh 1 more thing, the bleeder valve in the LS proportioning valve is stuck pretty good, so that is the only valve that was not bled. Is there air in there even though we are getting solid fluid out of both rear brakes? Again thank you for the help in adavnce

 

OK, I went ahead and replaced the master cylinder it was cheap enough to try at $34. We bench bled it, installed it, went ahead and bled all 4 corners again, and I still did not have any brakes, the pedal goes right to the floor, and doesn't get any harder with pumping. Very little air if any came through to any of the bleeders. This was with the truck running. Problem is when we tried to break loose the bleeder on the LSPV, it broke free from the mount at the top. The top brake line cracked,and it is so rusty, coroded that there is no way to grab ahold of the nut to get the line out that goes to the back brakes. So does anyone know where I can get one of these valves? Advance says goes to the "stealership". Does anyone know how much this might cost? I have a huge salvage yard within a hour or so of my house. They may have one. My thoughts are though that any truck that old in PA (mine is a 88) will probably look just as bad as mine does. What other years will work with a 88? Any advice/help will be appreciated, both with why there is no pedal, and with finding a part. Thank you

 

Get a manual proportioning valve.

Check your rear drums too for leaks.

 

Where would I get the manual valve? Advance Auto said they did not have a valve for the truck.

 

Ever figure anything out with this? I'm having the same problem where I can get the pedal to be firm unti I start the truck, then the pedal goes back to mush.

Rob

 

x2 that!
by the way some times the rear cylinders may not show a leak untill you pull the rubber boot off. Rear cylinders are so cheap you might as well buy some new ones while you have the drums off

 

Check out Elvotas writeup and mine:

elvotas
https://www.yotatech.com/forums/f116...c-swap-107749/

mine
https://www.yotatech.com/forums/f116.../#post50586263

These are rear disc brake conversions but we both installed manual LSPV valves

scrool through elvotas to find the part #'s you need and you can see how he installed his and then if you look at my writeup 3/4 down the page how i installed mine.

You MIGHT be able to find someone on here with a spare OEM LSPV but doubt it.. junkyard might be your best bet since its not a common part people replace.

I had and extra on but ive since chucked it sry =/

 

As soon as I found a new valve at a local junkyard, ($15) and bled it, the brakes work great. Sorry I got back to this this long after you asked.