Caseyrhe 650 Report post Posted August 30, 2020 New mst cylinder, new brake booster, rebuilt pro valve. I bled brakes and had a good hard pedal. Now that engine is running and pulling a vacuum to booster, pro valve is leaking and pedal is mush. I’m a little premature posting due to not knowing where exactly valve is leaking due to lack of having someone to hit brakes while I watch. Fluid level was low in reservoir for the front disc. Quote Share this post Link to post Share on other sites
Caseyrhe 650 Report post Posted August 30, 2020 Fluid shooting thru warning light sensor. So guess it’s bleeding by top seal replaced o rings on inner shaft and still does it another 3 steps back Quote Share this post Link to post Share on other sites
aslanefe 333 Report post Posted August 30, 2020 31 minutes ago, Caseyrhe said: Fluid shooting thru warning light sensor. So guess it’s bleeding by top seal replaced o rings on inner shaft and still does it another 3 steps back Are they o rings or seals on the shaft? Quote Share this post Link to post Share on other sites
Caseyrhe 650 Report post Posted August 31, 2020 2 O-rings and one seal screwed a bolt into the warning light sensor, pedal acts if it were manual brakes when started Quote Share this post Link to post Share on other sites
rwcstang 201 Report post Posted August 31, 2020 maybe incorrect seals? Disc Brake Distribution Block and Proportioning Valve Rebuild - How To 1 Caseyrhe reacted to this Quote Share this post Link to post Share on other sites
Caseyrhe 650 Report post Posted August 31, 2020 I found this kit on NPD and was able to print the pictured instructions. Got it ordered last night Proportioning valve.pdf Quote Share this post Link to post Share on other sites
Caseyrhe 650 Report post Posted September 5, 2020 Rebuild kit, 25.00 time spent, 4 hours time for it to leak, first pump Y’all Ausi’s better watch out, I threw that MF so far once I got it back off it might land down there tonight bore was pretty eaten/rotted but gave it a shot 3 giant steps back, ha ha ha Quote Share this post Link to post Share on other sites
Brian Conway 264 Report post Posted September 5, 2020 Pictured is the stock valve body on my stock power disc brake car. Included is the kit I used when rebuilding. Aside from the usual no room to work situation a relatively simple affair. Been a few years but no problems and do have reliable brakes. Brian https://www.musclecarresearch.com/valve-kit-wagner Quote Share this post Link to post Share on other sites
Mike65 475 Report post Posted September 7, 2020 Casey, when I installed the power disc brakes in my 69 Coupe I used an original looking reproduction disc brake proportioning valve & distribution block assembly that I purchased from Tony D. Branda Mustang in Altoona, Pa. I can not tell you the quality of the part since my Mustang is not running yet. Here is a link to the part. http://www.cobranda.com/19dibrprvaan.html Quote Share this post Link to post Share on other sites
Caseyrhe 650 Report post Posted September 8, 2020 Thanks Mike. 69/70 are different. I was able to pick up a new one at Summit and will install maybe this week. I like the rag joint bolt screwed in where the switch goes. I did the same when after the first attempt when it was bleeding thru. Quote Share this post Link to post Share on other sites
Brian Conway 264 Report post Posted September 8, 2020 not a rag joint bolt https://www.musclecarresearch.com/brake-valve-tool Quote Share this post Link to post Share on other sites
ralt962 11 Report post Posted September 10, 2020 If you need a good video on the rebuild check out the WCCC. Its Cougars but the part is the same. Just look up the part and the video is there. He does a great job walking through the rebuild of both parts. Quote Share this post Link to post Share on other sites
