4 wheel disc problems- solved

[64nailhead]

I should add that the stock prop valve works very well with any oversized front and rear disc setup. My car has Late 90’s exploder discs in the rear and oversized (58mm I believe) fronts with a MC conversion to manual from Malibu Dave. It works better than most can imagine. The car will go 140 in the quarter comes to a stop like my kid’s with the Vette stuff upfront. I’m running EBC Yellow stuff pads on stock front rotors. The yellow stuff pads take about a 1/4 second to heat up, then it’s like magnet pulling you backwards.

 

[81cutlass]

I also have had bad luck with aftermarket disk disk proportioning valves. I had a very squishy pedal with LS1 front and blazer rear disks. I swapped to the disk disk prop valve and it made it worse. Put a wagon B body caprice master on and kept the rest and it fixed my issues.

 

[silver46]

Thanks for the input. I have had my new delco mc for a few days now and customer cars are taking priority. Friday, back at it. The stops it made when the 79 disc disc master were working, were awesome. Right up until it would push fluid into the front chamber. I think I'll be mighty happy if this one acts like it ought to.

 

[silver46]

Solved-
So, I got a new ac-delco master, built for a 79 trans-am with 4 wheel discs. Bench bled it, installed it, then reverse bled the rear left and front left wheels, sucking extra fluid out of the reserviors as it appeared. This worked awesome. 45 minutes start to finish. Good firm pedal. Took it on a 25 mile cruise, pedal feels good and car stops like something modern! The wilwood adjustable proportioning valve works just fine. Thanks for all your help along the way.

 

[gnvair]

Front has new cross drilled rotors on stock spindles, and new larger bore gbody metric calipers. Rear has stock mustang rear rotors and calipers.

What size are the large bore metric calipers? Are they 2 1/2" or 2 3/4"?

 

[silver46]

What size are the large bore metric calipers? Are they 2 1/2" or 2 3/4"?

I think they're 2-1/2"