Toyota Rear disc brakes issue

itbrokeagain · 02-20-2011, 10:07 PM

Try a pressure bleeder if you can get access

Hotwheels · 02-21-2011, 07:59 AM

I have power bleed the brakes on my 4runner. The only thing I can think of at this time is I am using my stock ABS master cylinder and the rear part of the master is to weak and I need to change it to a non ABS master.

Hotwheels · 02-21-2011, 06:11 PM

So here is what I did today with the brakes. I have a 1" bore non ABS master cylinder on my 4runner. I have no proportioning valve and no 10lb residual valve on it at all. Took it all of to make sure it was not them. The runner had rear ABS and it is not hooked up at all. I have speed bleed the brakes and 2 person bleed the brakes and still have a ****ty pedal with the truck off and it goes to the floor when it is running. I am so fing pissed at this thng. I have also call sky and talk to someone there and he told me that everything I have done they would have done. So I am sunk any help would be great.

Rob

pfreer3 · 02-21-2011, 07:55 PM

When you bled them, did you do the farthest away first (Left rear, right rear, right front, left front) to make sure you got the air out?

check your vaccum booster check valve (in the line) to the intake manifold. If you took it off and flipped it around, that might cause the sinking pedal when its running. it has a direction so that once manifold pulls a vaccum, the valve holds it. I've seen this problem on 2 different rigs that had poor brakes after the conversion.

Is this a new master cylinder? If not, the one you have may be bad.

Brakes are pretty simple...

Hotwheels · 02-21-2011, 08:29 PM

The vaccum valve is fine I never took it off, it is holding vaccum. The master is new and yes I bleed the brakes the right way from passangers rear, drivers rear passangers front, and drivers front.

Hope Springs Hauler · 02-21-2011, 08:44 PM

I have seen bad MC's even though they were new. Ask FlxRtd:o

Hotwheels · 02-21-2011, 08:56 PM

I tried the master that was on my runner that was good. it was a ABS master and from what I have read that is not the master I need so i got a new master from Davez offroad performance. I really dont think it is the master.

02-20-2011, 10:07 PM	#1
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	Try a pressure bleeder if you can get access __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

02-21-2011, 08:44 PM	#6
Hope Springs Hauler Join Date: Jul 2008 Location: Hamilton, OH Posts: 431 Images: 16	I have seen bad MC's even though they were new. Ask FlxRtd:o __________________ 1988 Suzuki Samurai on propane FJ 40 axles (4.10) 5.14 tcase 36" TSL SX

02-21-2011, 07:59 AM	#2
Hotwheels Join Date: Aug 2010 Location: Maineville, Ohio Posts: 125	I have power bleed the brakes on my 4runner. The only thing I can think of at this time is I am using my stock ABS master cylinder and the rear part of the master is to weak and I need to change it to a non ABS master.

02-21-2011, 06:11 PM	#3
Hotwheels Join Date: Aug 2010 Location: Maineville, Ohio Posts: 125	So here is what I did today with the brakes. I have a 1" bore non ABS master cylinder on my 4runner. I have no proportioning valve and no 10lb residual valve on it at all. Took it all of to make sure it was not them. The runner had rear ABS and it is not hooked up at all. I have speed bleed the brakes and 2 person bleed the brakes and still have a ****ty pedal with the truck off and it goes to the floor when it is running. I am so fing pissed at this thng. I have also call sky and talk to someone there and he told me that everything I have done they would have done. So I am sunk any help would be great. Rob

02-21-2011, 07:55 PM	#4
pfreer3 Old Newb Join Date: Jun 2009 Location: Independence Posts: 49	When you bled them, did you do the farthest away first (Left rear, right rear, right front, left front) to make sure you got the air out? check your vaccum booster check valve (in the line) to the intake manifold. If you took it off and flipped it around, that might cause the sinking pedal when its running. it has a direction so that once manifold pulls a vaccum, the valve holds it. I've seen this problem on 2 different rigs that had poor brakes after the conversion. Is this a new master cylinder? If not, the one you have may be bad. Brakes are pretty simple...

02-21-2011, 08:29 PM	#5
Hotwheels Join Date: Aug 2010 Location: Maineville, Ohio Posts: 125	The vaccum valve is fine I never took it off, it is holding vaccum. The master is new and yes I bleed the brakes the right way from passangers rear, drivers rear passangers front, and drivers front.

02-21-2011, 08:56 PM	#7
Hotwheels Join Date: Aug 2010 Location: Maineville, Ohio Posts: 125	I tried the master that was on my runner that was good. it was a ABS master and from what I have read that is not the master I need so i got a new master from Davez offroad performance. I really dont think it is the master.