So I was driving my 1954 this weekend and after the vehicle is warmed up about 5-10 miles of driving it feels like something is causing a drag on the Truck.
The truck will no longer roll freely after a few miles of driving, I think either the brakes are locking up due to heat or there is a problem with the transmission.
I have a brake booster under the floor which is close to the exhaust. I have already re routed brake lines and sleeved them in heat resistant fabric. I am also planning to install a heat shield between booster and exhaust even though I am not sure this is the issue.
Anyone have any experience with anything like this? Any trouble shooting tips?
Sounds like maybe yer brakes are adjusted up a little to tight. And heating up when driving. I would try backing them off just a bit. When it is dragging have you went around and felt to see if there is any heat at any of the brakes? If any are hot to the touch than that is the one I would back off first.
It's more likely that yes it is the disks. My guess is the calipers are sticking. Also have ya checked the trans and diff for gear lube?
Anyway if ya think it may be the calipers than open the bleeders and let the pressure off. If it rolls free till ya use the brakes again than I would think ya found the problem. Sometimes this wont work but it is worth a try.
Depends on the caliper. If it's a single piston and the caliper floats on the mounting pin then you may need to grease up the pin they float on.
If it's a multi-piston and the caliper is stationary, like the Wilwood 4 piston where the caliper is mounted centered on the disc rotor, then the problem may be a residual valve.
You say you have disc/drum combo. You say the MC still under the floorboards with a booster there. Did you use residual valves? If so, are you sure you have the right size for the disc? The disc is blue (2lb) and the drum is red (10 lb). You don't need them for each wheel. Only for each axle.
I am using a Camaro Single piston Caliper. I am using the Blue(2lb) valves in the front. 1 on each wheel, and also 1 Red valve (10lb) going to the rear drums. I am also using a ford Combination Valve like the one listed on this page (1991 Mustang brake valve - Ford Mustang Forums)
I'm with Grizz. The aftermarket suppliers really push the inline residual check valves but they are, in my opinion, often overused and sometimes unnecessary. What is the original application of your master cylinder? If it came from a vehicle that originally had rear drum brakes, then you shouldn't need the 10 lb. valve in the line to the rear and I would remove it. Most master cylinders designed for use with drum brakes will have a residual check valve built in to the master cylinder. Adding another one can cause problems similar to what you are experiencing. The only time you need an inline RPV with drum brakes is when you use a master cylinder for 4-wheel disc brakes and that is true without regard for where the master cylinder is located. And as Grizz mentioned, you ony want one in the line to the front brakes. These things are notoriously "loose" with their specifications and you could have one holding more pressure to one wheel than the other.
So I thought I had this issue resolved but 2 weeks ago while out for a test ride I had the same issue....brakes locking up to the point that the pads were smoking hot.
I finally figured out what the problem was and am posting just in case anyone has a similar issue.
To summarize I have Mustang II front end with a bracket that lets me install the Grenada rotor with Camaro Calipers. It Turns out part of the casting on the caliper was hitting the mounting bracket not allowing it to seat properly. Calipers bolted on but never felt great since it was tweaked a little. This simple misalignment created alot of drag on the rotor. Well problem is now solved. Just wanted to share if anyone in the future has similar issues