F70 frozen / seized drum brakes


The last few times when we have had sub-zero temperatures overnight, one of the drum brakes (nearside rear) appears to be seizing on - I can notice the extra drag, and the handbrake feels 'loose & floppy' for the first bit of travel.

If I drive for about a mile, so the drum warms up it returns to normal.

I've NOT driven through any deep water, certainly nothing deep enough to touch the steel rims of the tyres.

The brakes otherwise appear to be working normally with no binding, and it recently passed an MOT.

I guess being drum brakes, if any water gets in them, it's much harder for the water to get out, WRT disc brakes.

My quick fix is to leave the handbrake off over night.

Anyone else had this problem / any suggestions?

1985 Veg oil burning Fourtrak "Rocky".

Playing the Drums

Water is not really the problem, it can be forming condensation which freezes, not generally a problem, but if the drum is scored water condensate can form in the bottom of the grooves.

This water will freeze, and as the shoes will wear to the groove, the raised bit of the shoe at their lower ends will freeze to the drum.


Remove the back brakes and check the condition of the brakes generally, of any scoring or a mormal ridge has formed have the drums machined flat in a lathe. Wear may cause problems, if the pistons come out too far they will tip sideways slightly and not return onto the slave cylinder, so check the adjustment and brake travel.

Check the operation of the handbrake, if the cable is binding on one side, this would hold the brakes on slightly.

One modification i make for vehicles operating in mud or water, specifically salt water; is to install a flushing system.

Drill the backplate at the top in an accessible position with a 12mm hole, paint any exposed metal and fit a blanking grommet. Drill the backplate at the bottom with a 4mm hole, paint, and install another blanking grommet.

Make an end to fit a hosepipe, i use a turned brass end with a short piece of copper brake pipe soldered in, bend the brake pipe 45 degrees close to its end. Clip to the hosepipe, remove both grommets and insert the pipe through the top hole, switch on the hose and simply flush the drum out.

Do not be tempted to use a jet wash as the extreme pressure can force water past the seals on the slave cylinder.

I'd be looking for water in

I'd be looking for water in the cable instead of the drum if I were you. It freezes and stops the cable moving so stops the brake from releasing off the drum when you release the handbrake. It gives symptoms exactly as you describe. If it happens again try pulling the brake on even harder to release the grip of the ice on the cable and then it should be fine until it freezes again. You can use a cable oiler (from motorbike shop) to force oil under pressure down the cable and hopefully push any water out. I made a homemade cable oiler which cost nothing and worked very well. If you want to know how to do it just ask.