500psi T-Bird Calipers

[ksagis]

1996 C2500 MC (A/C Delco 18M742) installed and working well.
2000psi at all 4 corners. Bench bled the hell out of it and bled all four corners making a huge mess and going through at least a couple quarts in the process.

Right now I have the front brakes on the forward port and the rear brakes on the aft port. I think this is opposite of how the C2500 was setup, but I'm exhausted and didn't feel like making another new hard line to swap them around again, but it is something I think I'll need to accomplish soon as the reservoir is not 50/50. The forward res is smaller than the aft res and my front calipers are much larger than my rears.

FWIW -the stroke of the HB output rod is appx 0.65"

Great news!

How far is the pedal moving?

The front pot (closest to radiator) isn’t the bigger of the two, at least it looks that way in the pictures?

Edit, the deeper aspect of the pot was throwing me off, I see now the volume created by the partition makes the front pot smaller

 

[toddz69]

So sounds like initial indications are that the master cylinder was the culprit. Have you driven it yet?

Todd Z.

 

[ZOSO]

Thats good news. I wonder what the issue was with that master? could it have been from such little HB stroke?

 

[chuzie]

How far is the pedal moving?

No change; same distance it was with the previous MC.

The front pot (closest to radiator) isn’t the bigger of the two, at least it looks that way in the pictures?

Front is larger port with smaller reservoir.

So sounds like initial indications are that the master cylinder was the culprit. Have you driven it yet?

Todd Z.

Drove it around the property on grass and gravel. Haven't put it on pavement yet though. Seems to stop much better in 2WD so I'm assuming there is more energy to overcome in 4WD with my low stall converter.

Thats good news. I wonder what the issue was with that master? could it have been from such little HB stroke?

Well, it's was either the lack of stroke or something defective in the MC. I should have pulled the piston just to know for sure but it's on the way back to Summit now.

The pedal still returns slowly with engine running. Returns quickly when off. I think this may possibly have something to do with using the Explorer PS pump. Maybe it doesn't have enough ass.

 

[ba123]

My pedal return was slow and I had to use my foot to pull the pedal back up for the first bit of driving. The WH docs do say that this can happen, so I just kept driving and it did go away. I do have an Explorer PS pump and it all works great.

Hopefully it goes away for you but if not then maybe there is something restricted in the PS lines and the HB unit. I hear a kinked hose can do it.

 

[chuzie]

My pedal return was slow and I had to use my foot to pull the pedal back up for the first bit of driving. The WH docs do say that this can happen, so I just kept driving and it did go away. I do have an Explorer PS pump and it all works great.

Hopefully it goes away for you but if not then maybe there is something restricted in the PS lines and the HB unit. I hear a kinked hose can do it.

Good point. I'll drive some more and see how it goes. Also running an 8" ram assist which probably contributes to bogging down the system.

 

[ksagis]

No change; same distance it was with the previous MC.

Front is larger port with smaller reservoir.

Drove it around the property on grass and gravel. Haven't put it on pavement yet though. Seems to stop much better in 2WD so I'm assuming there is more energy to overcome in 4WD with my low stall converter.

Well, it's was either the lack of stroke or something defective in the MC. I should have pulled the piston just to know for sure but it's on the way back to Summit now.

The pedal still returns slowly with engine running. Returns quickly when off. I think this may possibly have something to do with using the Explorer PS pump. Maybe it doesn't have enough ass.

Is pedal hard at the end of the throw? If not, I’m not convinced you don’t still have some small amount of air in system.

Given the increase in MC bore and likely somewhat compromised MC, the pedal travel should have reduced some from what it was.

The ram isn’t consuming fluid flow so for static steering wheel, it shouldn’t matter for pedal return. And the HB should be broken in at this point so don’t think miles would help on slow return.