1G Unsuccessful bleeding after CTSV brake upgrade - prop valve?

[talontime69]

I upgraded the stock 1990 (non-abs) front calipers to CTSV quad piston Brembos and can't seem to get these things to bleed.

I'm using the stock hardlines, prop valve, and master cylinder with stainless lines in the wheel wells to the calipers.
I've bled this thing no less than six times using a buddy in the car pumping fluid to Russell speed bleeders as I watch fluid, starting from the farthest caliper to the closest and ensuring all connections are tight and sealed. At least 32oz of fluid has been used in each of these bleeds.

The brakes will feel nice and hard after the bleed, I'll roll the car 5-10 feet to test the brakes after the procedure, nice and tight with stiff immediate pedal. I'll then drive 15-20mph in the driveway and the pedal will go to the floor, engaging only the drivers front and passenger rear as if the proportioning valve has locked them. I can "pump" the brakes while driving and the engagement changes all over the travel of the pedal. I suspected the master cylinder bore being too small so I installed (after bench bleeding) a 1 1/16 master from a 3000gt. Same symptoms. Nice and tight, then straight to the floor. I tried bleeding with the car on to use the booster to push out stuck air. no air.
I suspect the proportioning valve. Should I buy a new one?

Am I missing something? How would I go about resetting this valve or do I need to remove it and run fluid through it?
Thanks for reading and happy wrenching.

 

[Car Cannibal]

Had this happen before, left the brake line exposed for days thinking it'll bleed and I screwed myself, had to tow it and get the prop swapped and brakes bled by a shop. I think the prop can internally freeze up was the explanation.

 

[FIBA M - EC17PSE]

This is a frequent thing. The only way is to self bleed the master cylinder on itself as its an open type system. So once air is in then its very hard to remove it unless its self bled.

You need to bleed from the prop to the res / fluid pot till no air comes out. Once thats done have someone hold it shut/pedal down while you attach it again and then you can continue the rest of the bleeding. Its the only way without an air tool to bleed the MC as its always the MC on our cars that are an issue

 

[danl]

Sounds as if one of the master cylinder circuits has air like was said above. I just replaced and bled a master in my car and I can see where it can be tricky. Here is how I did it.

1. Pump brakes to extend pistons in the caliper.
2. Disconnect master cylinder lines.
3. Loop the outlet lines into the reservoir. Make sure the lines are submerged in fluid in the reservoir. You can diy flexible lines, but it’s worth buying them.
4. Pump the brakes slowly and consistently. On the up stroke the master cylinder pulls a vacuum, that is why you want the lines submerged. Keep pumping slowly until no air comes out on the down stroke.
5. Connect the oem hard lines to the master cylinder.
6. Push the caliper pistons back in. This will force more fluid into the master cylinder. Hopefully removing air if it exists.

 

[talontime69]

This is a frequent thing. The only way is to self bleed the master cylinder on itself as its an open type system. So once air is in then its very hard to remove it unless its self bled.

You need to bleed from the prop to the res / fluid pot till no air comes out. Once thats done have someone hold it shut/pedal down while you attach it again and then you can continue the rest of the bleeding. Its the only way without an air tool to bleed the MC as its always the MC on our cars that are an issue

So I take all 4 outlets from the prop valve and bleed them back into the master while the master is detached from the booster, then depress the pedal half way and reattach the master? How do I reconnect the hard lines to the prop valve without intruding more air into the valve? Thanks for your help!

Sounds as if one of the master cylinder circuits has air like was said above. I just replaced and bled a master in my car and I can see where it can be tricky. Here is how I did it.

1. Pump brakes to extend pistons in the caliper.
2. Disconnect master cylinder lines.
3. Loop the outlet lines into the reservoir. Make sure the lines are submerged in fluid in the reservoir. You can diy flexible lines, but it’s worth buying them.
4. Pump the brakes slowly and consistently. On the up stroke the master cylinder pulls a vacuum, that is why you want the lines submerged. Keep pumping slowly until no air comes out on the down stroke.
5. Connect the oem hard lines to the master cylinder.
6. Push the caliper pistons back in. This will force more fluid into the master cylinder. Hopefully removing air if it exists.

I will try this first without dicking around with the prop valve. Thank you! I’m now 6 months into a simple “bolt on” brake swap and I’m having boost withdrawals.

 

[FIBA M - EC17PSE]

So I take all 4 outlets from the prop valve and bleed them back into the master while the master is detached from the booster, then depress the pedal half way and reattach the master? How do I reconnect the hard lines to the prop valve without intruding more air into the valve? Thanks for your help!

not all 4 no, the 2 from the MC to the prop stay on, remove 2 from the front circuit ideally as it moves more air. attach a fitting to AN or flared fitting and hard line you whip up and then dunk it into the res pot, you can leave the rear fully attached still. once your air has stopped have someone hold the pedal down, keep it down and thats when you remove the bleed line and reinstall the oem line to the prop valve again, then the MC is fully self-bled and will be your best shot to getting it all air free

 

[danl]

Whatever method you chose, just be slow with pedal movement and leave the recirculation lines submerged in fluid. Watch how much air is purged out in the second method here:

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[stealthee]

Just to make sure, you do have the bleeders facing UP correct? I've seen people make the mistake far too many times. Would hate for you to be wasting your time when it would just be caused by a simple mistake.

 

[talontime69]

Just to make sure, you do have the bleeders facing UP correct? I've seen people make the mistake far too many times. Would hate for you to be wasting your time when it would just be caused by a simple mistake.

Yep bleeders are both up

 

[FIBA M - EC17PSE]

Whatever method you chose, just be slow with pedal movement and leave the recirculation lines submerged in fluid. Watch how much air is purged out in the second method here:

You must be logged in to view this image or video.

Only thing is on a mitsu unit you cannpt bench bleed a master. Mitsu is an open type system so allows air straight in once its released. While it pre lubes it but it 100% has to be bled on the chassis and then connected again in a closed position.

 

[danl]

Only thing is on a mitsu unit you cannpt bench bleed a master. Mitsu is an open type system so allows air straight in once its released. While it pre lubes it but it 100% has to be bled on the chassis and then connected again in a closed position.

Yup, I bleed them in the car. Sorry if I didn’t make that clear.

 

[FIBA M - EC17PSE]

Yup, I bleed them in the car. Sorry if I didn’t make that clear.

Its coo, i just dont want someone to think its an outside the car thing. It used to be mentioned to do this

 

[Detail]

Also, make sure your one way valve in your booster is 1: there, 2: working correctly. I had jammed mine into a hose only to find the hose collapsed.

 

[TerminalTalon]

It just sounds like there’s air in the system.
You need two people to bleed brakes or get one of those one way valve hoses. I still recommend two people. Pump 3 times, open the bleeder, the persons foot goes to the floor and close the valve. Do that until it’s a steady stream. After that troubleshoot. The person pumping can give you feedback on the pedal feel.Those also have two bleeders and they should point up. I’d bleed both twice just to make sure. Also any hose works into a submerged container of brake fluid to alleviate feedback. That’s why that one way valve bleeder hose is nice with the clear hose. You can visually see bubbles until it’s bled right.

 

[danl]

For those without a brand new master cylinder I would caution pumping to the floor. I caused a leak in the original 35 year old master doing that. Pumping half way is sufficient.

 

[TerminalTalon]

Also if getting a new master bench bleed it out of the car.

 

[Mello]

Now I'm confused -

Also if getting a new master bench bleed it out of the car.

Or. -

Only thing is on a mitsu unit you cannpt bench bleed a master. Mitsu is an open type system so allows air straight in once its released. While it pre lubes it but it 100% has to be bled on the chassis and then connected again in a closed position.

So which is right?

 

[FIBA M - EC17PSE]

Now I'm confused -

Or. -

So which is right?

Self-bleeding is correct. most modern systems CANNOT be bend bled. The amount of people I have doing self bleeding and then getting it working is like 95%+ success rate. Once you do this and remove the master with bubbles, you won't have issues unless your system has a leak along the way. It is how I have always done it, Others have done the say methord and its worked for us all with great success. its is fiddly I know and I will be looking into a kit to help with this but TWO people are always needed as you need to keep the system closed from air upon removal of the lines. it is not ideal, but it's the best way

 

[TerminalTalon]

Both are right. I’ve noticed on multiple cars that sometimes they need to bench bled first. Not to contain the fluid but to operate before install and to help the process. You are always going to need to bleed it.
If it was just a master you could crack the flares at the lines and pump until it’s steady. You need to bleed everything. Farthest back first so right rear, left rear, right front and then left front. Somebody check me if I’m wrong on that. Certain vehicles have different bleed procedures.

 

[Boosted1993]

I was going to make a new thread, but I am currently having this exact issue on my 2g.

Ctsv fronts with evo 8 rears. I have bled and bled these calipers for days now, and the same issue as the original poster. The pedal feels great initially, but once I drive the car, the pedal goes to the floor and also feels like it's applying pressure to the driver's front and the passenger rear. I have replaced the Master and bled it from the prop valve as described in this thread, and even used my pressure bleeder. I cannot get any more air out of the lines, and if the car doesn't move, it appears to have very good pressure to all 4 calipers. Once it gets moving, then boom, sloppy pedal until you pump it a few times, and then pressure and feel changes for the better just for a few seconds. I'm completely at a loss here.

 

[FIBA M - EC17PSE]

Both are right. I’ve noticed on multiple cars that sometimes they need to bench bled first. Not to contain the fluid but to operate before install and to help the process. You are always going to need to bleed it.
If it was just a master you could crack the flares at the lines and pump until it’s steady. You need to bleed everything. Farthest back first so right rear, left rear, right front and then left front. Somebody check me if I’m wrong on that. Certain vehicles have different bleed procedures.

Modern masters and even our old ones on the DSM do not require any bench bleeding. it is just adding mess and does nothing for it. so can skip that part for a faster and less messy setup

 

[FIBA M - EC17PSE]

I was going to make a new thread, but I am currently having this exact issue on my 2g.

Ctsv fronts with evo 8 rears. I have bled and bled these calipers for days now, and the same issue as the original poster. The pedal feels great initially, but once I drive the car, the pedal goes to the floor and also feels like it's applying pressure to the driver's front and the passenger rear. I have replaced the Master and bled it from the prop valve as described in this thread, and even used my pressure bleeder. I cannot get any more air out of the lines, and if the car doesn't move, it appears to have very good pressure to all 4 calipers. Once it gets moving, then boom, sloppy pedal until you pump it a few times, and then pressure and feel changes for the better just for a few seconds. I'm completely at a loss here.

do you have the calipers on the correct way around to remove ALL the air as I have seen some put them on upside down and then its not easy to remove the air!

As for the sloppy pedal. whats odd on that is if you bled it and the next day its still holding pressure, you have ZERO leaks. generally zero air also. This is the test of the system.
IF you're losing pedal after the start up then your issue lies generally with the booster and/or the check valve from the manifold to the booster.

Every DSM has a line to the booster with a check valve, and if you start the car and lose pedal, then the manifold is sucking the air, making you lose pedal. If you drive then you build pressure and create a stiff pedal until the pressure has dropped. So if the pedal goes when the engine's on and pedal gets lost its likely NOT the lines and air but the parts controlling the pedal.

 

[talontime69]

I was going to make a new thread, but I am currently having this exact issue on my 2g.

Ctsv fronts with evo 8 rears. I have bled and bled these calipers for days now, and the same issue as the original poster. The pedal feels great initially, but once I drive the car, the pedal goes to the floor and also feels like it's applying pressure to the driver's front and the passenger rear. I have replaced the Master and bled it from the prop valve as described in this thread, and even used my pressure bleeder. I cannot get any more air out of the lines, and if the car doesn't move, it appears to have very good pressure to all 4 calipers. Once it gets moving, then boom, sloppy pedal until you pump it a few times, and then pressure and feel changes for the better just for a few seconds. I'm completely at a loss here.

Did you solve this issue? I’m curious to what you found the problem to be.

 

[Stapl3]

No experience with the CTSV calipers, but I had to learn the hard way on my C7 calipers, which I assume are pretty similar, that the caliper has two bleeders on it. You have to bleed the inner first, then the outer. I only bled the outer as I had no idea there was an inner bleeder, and it gave me the same woes as posted in this thread.

 

[talontime69]

Issue solved:
Ended up not even being related to the hydraulics. Rotor runout caused by a washer I left on the hub when I was driving the lugs in. The rotor was pushing the pads around causing loss of pedal while moving.