"wooden" brake pedal

[oddbod]

i realise this may be unusual, but both my sons, who are learning to drive in our saloon Trundle, feel that the brake pedal has got harder to depress, NOT impossible just seems Wooden. We haven't adjusted the brakes for about a month or so. Any ideas as to the cause? The brakes are always better on a second application,but do not need pumping. I also think the pedal may be harder to depress but am at a loss to figure out why.Could this be impending Master Cylinder failure, the plunger inside getting stuck? The brakes still stop well, I can lock them at 20mph and stop in a straight line.

[bmcecosse]

There may be seized up wheel cylinders and /or oil leaked onto the shoes - drums off for urgent brake check....................

[oddbod]

Cheers BMC, I am planning to check when we get some dry weather (2013?) but wouldn't sticking cylinders mean the brakes were "stuck on"? And would then cause the wheels to be hot?

[autolycus]

The brakes are always better on a second application,but do not need pumping.

That suggests either incorrect adjustment or the top hat seal in the master cylinder not working correctly - in both cases the first press takes up the slack, the second applies the brake.

Could the pedal be stiff on its shaft?

I've never come across a master cylinder showing excess stiffness, and I think that if the piston were to partly seize, it would show up first by the brakes staying on and the pedal feeling floppy.

Wheel cylinders can seize in any position, so, as Roy says, drums off in turn and a systematic check of every cylinder. Wedge one shoe with a big screwdriver or tyre lever and watch the other one move while an assistant presses the pedal. Don't get carried away and pop the piston out. Make sure the rear cylinders aren't seized on the backplates.

If the learning sons are also having lessons in a modern car, the brake pedal will feel very different for them.

Kevin

[oddbod]

Thanks Kevin, I think stiffness on the shaft may be a possibility as I know the clutch pedal doesn't return to its correct position if the brake is pressed at the same time (when changing down to slow) and on driving Trundle earlier have noticed that applying the brake pedal moves the clutch pedal down slightly, so it could be the 2 issues are connected. I am quite impressed my sons noticed as they are not driving moderns, and are beginning to take an active interest in issues arising when driving our car. I am hoping they find time in their active teen schedule this weekend to jack Trundle up and whip off the drums!!

[Trickydicky]

Hi,

If it is the brake pedal shaft sticking, disconnect the pushrod from the master cylinder at the pedal, its only a split pin and a cotterpin (also dont adjust the pushrod) You can then feel if there is any resistance when you push the pedal by hand. If it is stiff then at least you can spray some WD40/Plusgas on the shaft and loosen it easily by pushing it up and down by hand.
I also keep a tin of spray white grease handy to use for times when you need to lubricate shafts or hinges.
Also you can inspect the master cylinder for any leaks with the cover off.

Richard

[lowride stepside]

Could also be worth checking the flexy hoses especialy the rear . I had the same sensation, and the rear hose had perished inside acting like a valve reducing presure to the rear ,very wooden