Bought a pretty modified fox that was not running and driving when I bought it. I've been picking away at it checking every nut and bolt(lugs nuts we're randomly loose on a few wheels) changed all the fluids and megasquirted it. Only issue I'm trying to figure out is the brakes. Pedal is solid like manual brakes. Has 5 lug 4 wheel disc conversion. I'm not sure if the booster is bad/not getting vacuum or if it has the wrong master or booster for disc conversion. Any help would be much appreciated.
Taking over somone else's project
- Thread starter Purplenotch27
- Start date
-
Sponsors (?)
mikestang63
SN Certified Technician
you are going to have to do a lot of diagnostics..
Did the PO convert to a manual brake setup?
what brakes are on their- rotors, calipers, booster, MC
If the booster was bad the pedal would sink to the floor and not come back up when you start the car with your foot on the pedal
with the car off, put your foot on the brake and hold it, it should NOT go down
when you start the car it should go down and then rebound when you take your foot off
Do you hear any hissing when you depress the pedal
did you check the following
check valve on the booster
line from the booster to the Vacuum tree.
Post pictures as those help
That is why I hate buying modified/hacked up cars and prefer to get them as stock as possible and build them the way I want
Did the PO convert to a manual brake setup?
what brakes are on their- rotors, calipers, booster, MC
If the booster was bad the pedal would sink to the floor and not come back up when you start the car with your foot on the pedal
with the car off, put your foot on the brake and hold it, it should NOT go down
when you start the car it should go down and then rebound when you take your foot off
Do you hear any hissing when you depress the pedal
did you check the following
check valve on the booster
line from the booster to the Vacuum tree.
Post pictures as those help
That is why I hate buying modified/hacked up cars and prefer to get them as stock as possible and build them the way I want
Thanks for the info. The pedal is rock solid when running. Don't hear anything hissing. Ill recheck the vacuum lines tomorrow. How can I check the valve on the booster? I'll post pics in the morning. Thanks again
Looks like it's the stock master and booster with gt v6 brakes. So I'm guessing I need the booster and master for a better pedal feel and brakes I don't need to put my foot through the floor to stop.
Attachments
Yes. Stock MC and booster and 94-98 GT/V6 brakes.
What's out back? My answer will depend on what the rear setup is
What's out back? My answer will depend on what the rear setup is
So looks like you have 94-98 GT/V6 brakes front and rear, but running the stock MC and booster.
That pedal combo should be extremely soft, not hard like you are experiencing. Judging from the looks of the brakes, and lack of contact on that rear rotor, I would make a guess that one or more of the caliper pistons are seized and that's why the pedal is so hard.
It's not the correct MC/Booster combo anyway for the brake setup. You should be running a 94-95 GT 1 1/16" bore master cylinder and a 1993 Cobra booster. However, I think your brakes have other issues going on, and what I mean by that is seized calipers or slide pins or possibly no vacuum at all at the booster.
Engine off, pump the pedal until it's rock hard. Start the engine, and the pedal should sink once vacuum begins to pull from the booster. That braided vac line to the tree is interesting, but it probably is leak free. It's not uncommon for a MC to leak out the back into the booster and destroy the diaphragm giving you a huge leak.
I'm banking on seized calipers though. Jack the rear end up to get both wheels off the ground. STart engine and get the rear wheels spinning and lightly apply the brake. Can you stop the rear wheels easily?
That pedal combo should be extremely soft, not hard like you are experiencing. Judging from the looks of the brakes, and lack of contact on that rear rotor, I would make a guess that one or more of the caliper pistons are seized and that's why the pedal is so hard.
It's not the correct MC/Booster combo anyway for the brake setup. You should be running a 94-95 GT 1 1/16" bore master cylinder and a 1993 Cobra booster. However, I think your brakes have other issues going on, and what I mean by that is seized calipers or slide pins or possibly no vacuum at all at the booster.
Engine off, pump the pedal until it's rock hard. Start the engine, and the pedal should sink once vacuum begins to pull from the booster. That braided vac line to the tree is interesting, but it probably is leak free. It's not uncommon for a MC to leak out the back into the booster and destroy the diaphragm giving you a huge leak.
I'm banking on seized calipers though. Jack the rear end up to get both wheels off the ground. STart engine and get the rear wheels spinning and lightly apply the brake. Can you stop the rear wheels easily?
One of their guys is going to come over and tune the car so I can drive it to their shop and then we are going to schedule a day that I can bring it and get it fully tuned
I did some digging around today and I'm pretty sure the booster is bad. I bled the brakes and while doing so I tried spinning the wheels once it had pressure and they lock right up. I ordered a master cylinder and booster to match this set up. I'll let everyone know on Saturday when it's all installed. Thanks for all the help
