Flushing rear brakes was difficult

[Jstyle]

So I’m taking the Supra out for an HPDE event in a few weeks so of course it’s time to take out the stock brake fluid and put some good stuff in there.

I always use a one man bleeder that has a check valve that doesn’t let air or fluid in when I release the brake pedal to make things easy. So I started in the passenger rear like you should and I was surprised that it didn’t matter how much or how little I turned the bleeder screw the brake pedal was pretty tough to push down. What makes it even more interesting is when I stopped pumping the brakes after about 30 seconds little air bubbles would start forming in the hose (again it’s a one way check valve and it’s super tight over the bleeder screw).

Eventually I moved to the front and didn’t have the same issue. The brake pedal went all the way to the floor nice and easy… it was only the rear brakes that I have the tough push down and the air bubbles.

thoughts?

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[DarkZupra]

So I’m taking the Supra out for an HPDE event in a few weeks so of course it’s time to take out the stock brake fluid and put some good stuff in there.

I always use a one man bleeder that has a check valve that doesn’t let air or fluid in when I release the brake pedal to make things easy. So I started in the passenger rear like you should and I was surprised that it didn’t matter how much or how little I turned the bleeder screw the brake pedal was pretty tough to push down. What makes it even more interesting is when I stopped pumping the brakes after about 30 seconds little air bubbles would start forming in the hose (again it’s a one way check valve and it’s super tight over the bleeder screw).

Eventually I moved to the front and didn’t have the same issue. The brake pedal went all the way to the floor nice and easy… it was only the rear brakes that I have the tough push down and the air bubbles.

thoughts?

Was the parking brake engaged?

 

[Jstyle]

Nope... Maybe I should have put it in neutral or something... I dunno.

 

[DarkZupra]

Ive never had this issue but I use a power bleeder instead of pressing the brakes.

 

[razorlab]

Motive bleeder works wonders and saves relationships.

That said, the rear brakes def bleed at a trickle compared to the front, but it still works! Done it probably 5x on the Supra now.

 

[nibble]

does it do that both side of rear? or just one side? if so, which side?

 

[dzeleski]

Im not a huge fan of those check valve bleeders. I used a motive power bleeder as well and had zero issues bleeding the rears or fronts.

 

[Jstyle]

It was both sides. It came out, it was just really slow compared to the front.

 

[Xproplayer]

Just did a bleed on all 4, but I wasn't the one on the pedal. I'd say the rears were indeed slower, but I also didn't drain any of the original fluid so I was doing the rears for a liter of fluid before moving to the fronts. Another theory is ABS / TC modules that use the brake fluid?

 

[Jstyle]

I know there is some left in the ABS pump but it is what it is. I'm not paying hundred to have that flushed... At least not yet.

 

[nibble]

I do gravity bleed and has been working for me. although it take more time to to flush out rear brake, it drips about as same rate as front would.

 

[Jstyle]

Hey what's up with that piece on the master cylinder that looks like a straw for the side. Is that for draining the master cylinder or what? If so how does it work, do you just unscrew it or...

 

[dzeleski]

Hey what's up with that piece on the master cylinder that looks like a straw for the side. Is that for draining the master cylinder or what? If so how does it work, do you just unscrew it or...

Just a guess but most likely used for manual versions where it can share the same fluid for the clutch master. For Autos they just pinch that off and plastic weld it. Cheaper to do that then have multiple parts.

 

[JRedMKV]

Hey guys I could use some help please. I changed my brake lines to stainless steel and when bleeding the rear brakes using a Motive power bleeder no matter what I did there were tons of little bubbles coming out. I checked for any leaks and there were none. The pressure in the motive bleeder held steady. After flushing each side more than a liter I moved on to the fronts and there were no bubbles whatsoever coming from the fronts. Any idea what’s going on?

 

[Eddie21]

Motive bleeder works wonders and saves relationships.

That said, the rear brakes def bleed at a trickle compared to the front, but it still works! Done it probably 5x on the Supra now.

I got the motive bleeder also and am going to bleed my brakes, do you leave your ebrake on or off when you do yours?

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