sweetride5.0

hey there every one , pretty new to yotatech but i picked up a 88 toyota pickup and i replaced the calliper the wheel cyllinders the master cyclinder and 80% of the brake lines and i bench bled the master well i have a siff brake pedal when truck is not running but when truck is the pedal goes straight to the floor, dont know whats wrong ive put 2 litres of brake fluid through it and have been bleeding for 3 days straight NO LEAKS are detected and bleed for 3 hours a day for 3 days straight like i said idk is there any other way of getting the air our of the lines i bleeed them in order like i said i just dont know how theres still air in the lines HELLLPP pleas i want to put the truck on the road be for winter thnx to anyone with anwsers

dropzone

iTrader: (6)

Moved from site feedback.
Check all your connections again. Air is getting in somehow or you have a bad master cylinder(yes brand new ones can be bad)
Are you bleeding the LSPV above the RR wheel?
You can down load the service manual using the link in my signature.

And hit the period or return every once in awhile

sweetride5.0

yah i got a service manual for it and yah im bleeding he LSPV as well and i checked all the fittings and made sure they were all tight with line wrench and no air was coming in or out can i get air out by gravity bleeding it ? or how does the vacum pump tool work :S the only thing ive seen in the local parts stores is the one man bleed tool were its just a bottle and a tube (no pump) like i said this is the weirdest problem ive had and i made welded closed some old brake lines and screwd them on the master cylinder and i couldnt even push the pedal down at all the the master is holding its pressure and not leaking through it so i CANT be the master lol i rulled that out it has to be air i just dont know how to get it out other then keep bleeding but like i said this is gunna be the 4th day of bleeding it like i put already 2 litres of fluid thru it lol how much more i gotta buy lol so what are some more methods of bleeding for these trucks ? thx again

xxxtreme22r

subscribed, I got a similar almost identical problem going on that has me boggled. Your ebrake works properly right?

dropzone

iTrader: (6)

Dude seriuously try some punctuation every now and then.
Bleeding in the correct order?
I know of members who have gone through three master cylinders new out of the box.

xxxtreme22r

In my case I hadn't replaced anything it just started showing up. My fluid level in the master was mysteriously low. I still haven't looked at my newish wheel cyls nor bled my brakes after having low but not empty fluid level. Master is newish as well. My ebrake wasn't working properly shortly after symptoms started, thought maybe pedal catching low was mis adjusted rear brakes after a mud bog as I have had that problem before. Nope.

Ebrake works good now. I did however have quite a bit of mud (go figure) in my calipers that might have led to me blowing the master. I haven't taken the master off the booster yet, but I have a feeling since I can't see any fluid loss that it blew out the rear and collected in between the master and booster. I have seen this before as well. But again, I haven't taken the drums off to check for leak(s) at the wheel cylinders.

My quick question is, is it possible for the wheel cylinders to overextend and leak fluid temporarily due to a bad adjustment/wear of the shoes? And then get retracted somehow and once again hold fluid.

P.S. All my brake parts are less then a year old with the exception of the booster, calipers, front lines and the drums themselves.

Also, is it possible since the LSPV senses front line pressure for something internal of that to fail where it "thinks" the front lines are "broken"?
Still doesn't account for my fluid loss though. Which is tricky anyway since currently my low level light don't work.
(t-100 master and lack of sensor pigtail). Unfortunately I don't have a habit of checking brake fluid level so the fluid loss could have been "slow"

93toyrunner2

Are you using fresh fluid? If a bottle of brake fluid has been opened for more than a year, throw it out and get a new one.
Have you cracked every single connection in the lines from the master cylinder, proportion valve, line joints, all the way to each wheel? If there is an air pocket in the lines somewhere, doing this will help with pushing it through. You need an assistant to pump and hold while you crack each line nut at each fitting. Use a good line wrench so you don't strip them!
Procedure requires an assistant:
pump, pump, pump, hold (until you tell them to release and pump again)- crack and close fitting. When there is no more fluid coming out, close your bleeder/fitting and ask your assistant to remove his foot from your brake pedal.
pump, pump, pump, hold - crack and close fitting. 3-4 times per fitting as you work your way to each wheel. On the last crack and close of each fitting, do not wait for the pedal to go all the way to the floor, just open it and close it quickly.
Check fluid level after each fitting bleed. Once you get all of them done, then work your way from the furthest wheel to the closest wheel from the master, bleeding only the the rear wheel cylinders, then the front calipers.
RR, LR, RF, then LF
This is what I was taught by a Ford Motor Company Master Brake Engineer during training a few years back.
Hope it helps.

xxxtreme22r

Cannot forget about the bleeder on the LSPV. So it would be RR LR LSPV RF LF. But I remember someone telling me the LSPV should be done BEFORE doing the rears.

snobdds

Last time I replaced my break pads and bearings, I had a hell of a time bleeding the brakes also. I just ended up making 5 different holding containers with a long run of tubing going to each of them. I filled the master cly. up and opened all the bleeders slightly, pumped the brakes a couple of times and just gravity bled them for about an hour. Replacing the fluid as needed. I went through about 2 quarts of Brake fluid.

Then I tightened them all up and bled each brake normally. It was the most involved process I ever went through. But it worked. For some reason, Toyota brakes have always been hard to bleed.

93toyrunner2

Yes, when you are working your way from the master following individually through each line to each wheel, then the LSPV is bleed before each rear wheel. Once you have bleed the entire system, and you are on the second round, you only bleed at the wheel cylinders or calipers (4 locations).

greencactus3

id just go get some more MCs. took me 3 tries to get a working one.

xxxtreme22r

FSM has you bleed the rears first then the the front then the LSPV last though. Which is odd.

snobdds

I have always done it with LSPV last. Always...

93toyrunner2

If you have little or no pressure coming out at the master cylinder when you start the bleeding process, then another MC is needed. If you have pressure when you crack the lines at the master, keep bleeding the system.
In my experience, I have knocked out several tough to bleed systems by following the fluid flow from the master all the way to each end point, moving the air out or further down the line each time.
Be sure to update us when you get this solved.

sweetride5.0

hey guysi just was out working on the truck breaks again and still no luck add another 3 hours to the brake bleeding lol im doing every thing the books tells me and doing most of the stuff you guys are telling me like cracking the lines and not letting the pedal hit the floor befor closing the bleeder ( well the assistant tells me b4 it hits the floor) like i dont know guys right now its sitting out there gravity bleeding lol its the only thing i havent tried yet but "93 toyrunner2" u have a good point about cracking all the connections then bleeding so im going to wait a hour after gravity bleed and bleed the fittings then bleed the brakes in order again lol i got another 1L of brake fliud and yes to the question about new fluid i am using new fluid no old stuff lol i think its the caliper holding the air when i did bleed it b4 i gravity bleed it i opened the LSPV and a bunch of air came out i bleed it 3 or 4 more times and just fluid came out so figured no more air but i did do all of them in order

sweetride5.0

sorry about punctuality lol just 19 and im use to facebook chat so and MC is good bought it yesterday and made sure it had pressure i cracked the line when assistant help the brakes on and pedal went to the floor so not MC its a mystery where the air is and how many times i got to bleed it till it comes all out i know there's a big pocket of it some where just not sure where

xxxtreme22r

I got most of my pedal back just by bleeding it. However....... Like mine does pumping your brakes bring the pedal back? On first pump of mine it almost goes to the floor, but the next 1 or two pumps, the pedal is back to firm. This is while it's running and driving not when off. At this point I am thinking master.

93toyrunner2

If the pedal doesn't drop after pumping it up, then yes, MC. If the pedal drops (vehicle running) after pumping it up, then leak in booster or leak in lines.

snobdds

I fixed it for you

xxxtreme22r

ok so if snobdds is right then have none of those symptoms. As my peal stays hard when pumped and engine off. But When engine on It gets harder when pumped (starts low). Still say it's the MC. I guess we will find out this weekend maybe. At least on mine.