drew303

Before I replaced my rear drums to disc. I went through hell... which led me to replace them with discs. LOL

I replaced a wheel cylinder with a brand new one... only to have it faulty. Then be called an idiot at the parts shop when i returned it. Then making them give me a new one of different brand and it worked.

Anyway... you might have a faulty new wheel cylinder, or your other one has blown. The idea of knowing that new and old wheel cylinders can fail is scary ... Imagine this happening on the freeway?

I'd replace both rear wheel cylinders and check that your LSPV isn't faulty as well (even more rare but not unheard of)

Then when you finally are completely fed up with drum brakes because they suck balls,

take a look at these links

http://board.marlincrawler.com/index.php?topic=55953.0

http://board.marlincrawler.com/index.php?topic=57821.0

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

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

oh... my brother and his friend were doing the brakes on a Nissan Frontier.. they couldnt figure out why the pedal was limp.. So they asked me to come out and lend some assistance. I looked at it. .. hmm brake fluid is brown... I told them regardless you should bleed this fluid just to replace it because its bad. They did, they bled all 4 corners and weren't to happy about doing so. It's a pita on a 2wd low riding truck =p

pedal was better, no surprise to me but still no good.

So I said, pull the wheels off, let me look at the calipers and your job. I took one look at each, laughed, said, fix those clips and i bet you, you have brakes. Hard to describe but the lil spring that held the pads in on those particular calipers, was caught between up on the pads holding them off the rotor just scooch. But even a mm movement is to much as far as brakes are concerned. The system isnt designed to have that much travel.

They fixed the clips and brakes were fine.

might check your front calipers to make sure the pads are mating (static) with the rotors, same with the rear drums. Excess play will cause a limp pedal. IE the pedal travel isnt enough to move the amount of fluid needed to move the pads/shoes.

ITrain

Thanks for the advice. I'll pull the wheels and check. I know the front's are good. I haven't touched the backs though. The rears are way out of adjustment anyway.

Here's another issue i'm having. The remanufactured MC's i'm buying don't match the VIN number i have. Here's how i found out: I was bleeding the MC on the vehicle with the tubes they provide but was getting a bunch of air out of the back port. (the one for the rear brakes). So I took it off and bench bled it. Turns out my push rod isn't activating the entire MC.

So I adjusted my push rod so that it just contacts the MC when installed. Therefore, getting the max push. Now my pedal only goes half way to the floor before it bottoms out the MC!

I called the parts store and it turns out the replacement MC numbers don't match my VIN. My 8th "number" is an A, and they don't have a MC with that "number."

So I called Toyota they have one that matches my VIN for 225!!!

I don't know what the problem is now!

superchevyguy

I'm having the exact same problem. I've replaces the entire system. Mc, booster, calipers, pads, shoes, and rear wheel cylinders. Everything is new. I've bled them with the motor running and turned off. I've gravity bled them, done the 2 man method, and used the one man bleeder gun. I've been doing this for 25+ years and I just can't figure it out. Only the rears won't bleed. Bench bled the mc, no air. I don't get it!

85gijunk4x4

do you have any pedal pressure

superchevyguy

Not sure about the other guy, but I have very little.

ITrain

I have bought a aftermarket (Summit) brake proportioning valve. I tore mine apart and it was definately froze up and rusted. I freed it but believe it is not working properly. I'll let you guys know how the Summit BPV works. I should be doing a complete rear brake rebuild soon.

Yay4yotalove

Ok i have a a big problem.....i removed/bypassed the lpsv i have amazing pressure when i bleed the brakes with 94 4runner off...i turn it on, peddle drops to the floor??? i havent bleed the MC yet but tomorrow i'm trying that. i caped off the L union that goes to the rear...does both lines that come out of the MC create pressure or is it a loop that has to be connect in order to work???? i'v just tryed gravity and two man methods.

dhall50

Okay first things first? Shouldn't you bleed the the drivers side rear first? It is the furthest from the MC? Anyway, I had a a leaky MC that had leaked into the brake booster. Make sure this has not happened. Next: The rod for the brake booster is adjustable. Mine was adjusted too short and was not pushing deep enough into the MC there for not applying enough pressure even with the pedal all the way down. Dont adjust it out too far or the brakes will be applied all the time.

Best of luck.

thook

Yep. Driver's side rear first.

Zelephant

This just happened to me also. I'm replacing both with V6 components. Hopefully I don't go through the bleeding nightmares you guys are having.

ASE35YEAR+

[FONT=Times New Roman]I note the year but not the make or model my question is does your system have a proportioning valve and if so did you lift it when bleeding the system. If not you will need to start from the beginning. Adjust brakes, bench bleed the master, relieve the proportioning valve, then starting the farthest bleeding point from the master and bleed the system and release the proportioning valve. Bleeding at any time with two people is not best way, best way is to use a bleeder that uses pressure or vacuum to work both work great.

thook

Mind if I ask why you say this? Also, if you wouldn't mind rephrasing your last sentence. It's completely illegible.

kasko

I have had the town mechanic tell me to avoid at all cost remanufactured MC's. So i always get new (not from dealer) for peace of mind

oldskoolstang

One tread I have certainly noticed on all of the threads involving brake problems or brake bleeding problems is that no one seems to ever post what actually worked to fix their problem. I have a similar problem and have yet to find a solid solution anywhere on this site as well as on several other Toyota sites. Apparently these brake systems with the lspv are just crap. I have been battling with mine for 3 days straight and prior to 3 days ago I've never had a single problem for 16 years and 175k miles. But now that I do have an issue it seems that I may not be able to fix it and I work on cars non-stop.

JeffToyota

I had this problem a few years ago and here's what worked for me. I used a vacuum bleeder and did the process in REVERSE. Start and the closest to the master cylinder (driver's front) and work towards the furthest (passenger rear). I'm sure it works with two people using the foot pump method.

TNRabbit

Lifesaver!

Duffdog

Well, I had the same problem with my 4runners after lifts etc. Finally, I had to extend the rod that connects the brake proportioning valve to the axle. Nothing else worked, it seems that if the valve gets set in the wrong position EVER, your rear brakes just don't work. Not to mention you can't bleed them.

So, if you simply lengthen the LSPV rod, I think all your troubles will go away. The advise of "raising" the bar that connects the axle will work for a short time, until the valve closes off the fluid again after it is returned to the wrong setting.

85gijunk4x4

lol, thats reverse?? ive always grew up bleeding brakes starting with the caliper/drum closest to the mc first. but hey, ill try it the regular way next time and see how i like it

Dwman

Replaced brake caliper. Can't get that wheel to bleed or can't get brake pressure. the other 3 wheels bleed just not that one. What am I doin wrong?