Locking Front Brakes
 

Hi, I am looking for some advice please. I have a 1950 F1, it is mostly original save for the Mustang 2 front sub frame with of course rack & pinion steering and disc brakes. I have not had the truck long and have had a few issues which I am getting through. The latest problem is that if I have to brake heavily the front brakes lock up way to easily. The front end was fitted over here in the UK, and looks to be a really neat job. I see under the bed someone has fitted a valve in the brake line, presumably to balance the brakes front to rear. I have booked the truck in next week at a local garage to get it on there roller brake tester. I was thinking that before I go to the garage I should check the rear shoes for adjustment. Do I need a hub puller for this or do the drums just slip off like our 60's UK Ford cars did ?. Any advice would be most welcome.

Suffolkman

Rear drums just slide off once the wheel is removed, but you don't need to remove the wheels or drums to adjust them. Put the axle on jackstands, and rotate the wheel forward while adjusting the star wheel inside the brake until you feel drag. Press the brake pedal to re-center the shoes then re-check for drag. You want a slight amount of drag, more a sound than difficult to turn.
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Pic: 1974/78 Mustang II power disc brake system. Notice 2B257 (at right center lower). This is the Brake Pressure Differential (that some people call a proportioning) Valve.

I would assume that the aftermarket Mustang II set up would have something similar.

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Thanks Ross, that looks easy enough. The kind of stuff I used to do on my UK Ford Cortina and Anglia 105E 45 years ago !. I will check them tomorrow. I have purchased the Ford F1 Shop Manual, but I havn't found it that useful so far. You are a mine of information sir.

Suffolkman

Thank you for your reply. I will get underneath and see if I can find the is valve on the front end. Like stated I have found a valve fitted under the pickup bed presumably to close and open the rear brakes. I am guessing that the company that fitted the front clip also fitted this. I will give them a call tomorrow.

If your front disc brakes are locking, check the location of the master cylinder If it below the calipers, you will need to put a 2 lb. residual valve in the circuit. This will prevent siphoning of the brake fluid back to the master cylinder.

I had this problem when I put disc brakes on my ’56 but kept the original master cylinder which was located on the frame rail. The front disc would lock and then after sitting return to normal. It was a difficult problem to diagnose at the time.

Hopefully, you will find a fix for your problem.

Yes, it sounds like there is a residual check valve in the line to the rear . . . but CPP master cylinder booster kits have it built into the prop valve under the MC. It should be 10 lb.

And if your master cylinder is mounted under the floor you may need to add a 2 lb check valve in the line to the front. If you are using both ports in the front (2 lines L & R) you would need 2 of them.

Thank you for your reply. I have adjusted the rear shoes now. On Wednesday am taking it to a rolling brake tester to see what we can find.

Suffolkman