brake problems

[high4runner]

ok so im not a wizard when it comes to brakes but i got a problem and i cant figure it out. i got this truck from a dude awhile back...ive never driven it cause its just a trail rig that im building up but when i bought it i was told it had air in the system and i needed to bleed the brakes. no prob...i atleast know how to do that. well that didnt work. there was no air commin out either. so now i just replaced the master cylinder. i DID bench bleed it b4 i put it in. everything is put back together but i have yet to find a buddy to help bleed the brakes. i have pushed the pedal and it just doesnt seem to build pressure.?? any ideas?? thanks guys.

[keyice]

sounds like you have air trap and the bleeders are all plugged, pull the bleeders out and clean them. Also if you need to watch the seals if it isn't a new master cylinder the remanunufact ones offen have bad seals because they use soft cheap ones instead of the toyota factory ones so they get ripped really easy. also most people don't turn the self adjusters out in the back when they take the drums off and put them back on try turning them out remove the rubber plug and turn wheel with screwdriver

[high4runner]

hmm...well my buddy just left....we bled the brakes....still nothing. cant see any leaks....fluid comes out of all bleeder valves yet the pedal still goes to the floor. even with pumping it wont build pressure.

[superchargedtoy]

I had the same problem try bleeding at the proporting valve right above the back axle should be on the pasenger side.

[WrenchTwister]

lspv should be bled last, but if you cant make any progress, try it.
are you pumping, holding and having your buddy open the bleeder?
RR, LR, RF, LF, LSPV. using that order?

[fourwd1]

It's LR, RR, RF, LF, LSPV

[keyice]

sound like you really have a lot of air, if you have access to a vacuum bleed you might want to go that route, bleed the driver rear first, pump until you get solid fluid refill the master cylinder and go to pass rear, them portioning valve, then the pass front, drivers last do that cycle a couple of times, I had a similar one on a 85 turns out someone left the self tensioner out on the pass rear.

[high4runner]

ah crap...i didnt know that valve was supposed to be bled?? i have just been doing the wheels in the order you guys have been sayin. today i took off my drums to check the clearances....that checked out ok. i was gonna do a gravity bleed on it, but i think ill hold off and try plain old bleeding again tomorrow and bleed at the pv also. thanks guys....i hope this works!!

[81toy4x4]

Do you still want rear brakes? I could have Lloyd make up a couple more plugs like we did on my 84 (still not done, Finals week took up a lot of time, but all that's left is rear shocks, front bumper, and taillights). If you don't want rear brakes that should fix any problems you can imagine having with your rear brakes.

[high4runner]

yeah, might have to take ya up on that alex. i got a vaccum bleeder tonight...f$#@ i was getting alot of air out of all bleeders. the kit instructions called to do the closest to farthest...so i did that first...then went to farthest to closest...still nothing....just air bubbles and fluid...re-filled the master bout 4 times..maybe more...lost count. anyways....i do know that the guy that had this truck b4 me replaced the lines going to the rear...if he had done this how much air would be in the system?? how many times do i need to pump this damn vaccum thing....damn hand is getting tired...and im getting pissed off... :mad:
by the way alex my trailer is finished minus the ramps and wheel wells which im doing this weekend....2 weeks later ill be doing my exo cage and putting my mile high package of parts on.

[ZUK]

high4runner---Just for a test, why don't you dis-connect the rear axle mounted proportioning rod and tie it up to the bed for a test run. With the rod tied up, you will have maximum pressure to the rear brakes....see if that does anything.

[81toy4x4]

I should have my truck done here shortly, sorry I didn't call ya back last night i've been super busy, but i'll have lloyd make ya some plugs and i'll call ya when they're done. I gotta get mine in there for an exo cage after I paint it, so maybe in a month or so I could have it in there? Anyways, I'll ttyl, i'm back to being busy.

[high4runner]

thanks zuk....i'll try that in the morning. im getting super frustrated. i think that there has to be a leak somewhere?? i followed the lines and didnt see anything so i figured maybe the calipers or cylinders are bad? well i put in new calipers tonight....still getting alot of air. when i had the drums off i didnt see any wet spots where the rear cylinders could be leaking. im stumped. could the rear porportioning valve be shot without leaking?? i will try tomorrow disconnecting it and see what happens.

[81toy4x4]

I got your brake plug offs made, i think i forgot them at the machine shop around the lathe or mill or something, maybe at the cnc machine though, lol, who the hell knows, anyways i'll grab em tomorrow!

[KToy]

no fluid in the drums in the rear. sounds like a leaky wheel cylinder...

[Leigh Shonosky]

Im having the same problem with my 86. I replaced all lines and calipers in the front and i removed the prop valve and pluged the return line. I have bled the brakes about 15 times and cant get them to work right. the first half of the pedal is no resistance and then from half way down the front brakes grab and hold if i push right to the floor. I find if i pump them twice when I go to stop the pedal will get hard at the top of the stoke and the back brakes work.
I as well dont have any leaks ???? If any one has any suggestions?

[KToy]

u need a proportioning valve....... summit racing has them./

[keyice]

okay bubbles, fluid, bubbles, you just have air in the system, if you are using a power bleed, aka vacumm bleeder it still has to be above the lines to the porptioning valve just did all mine on my 82 when I swapped both axles pumped three full master cylinders into the lines by leg and bottle, always do the farthest first, leaky wheel cylinder leak out of the drum bottom, pump the pedal till it is firm them open the bleeders that force the air to that front, also might want to bleed the lines at the m cylinder first that helps to