my diff is very nice and smooth and easily pushed my hand when moving the kit car however after a hard run it seems to start "seizing " if you like like you leave the handbrake on a little its not bad bad but it is certainly noticable what is this ?
is it the diff ? oil in it low ?
or am i looking at a different problem as after i cant push the kit car backwards (bike engine) but after 15-20mins its fine you can push it with one finger :-/

thanks to anyone who can help me

Are you sure it's the diff and not the brakes?

im not sure its the diff but i wondered how would the brakes tighten up after hard run ??
then leave it 15mins after driving and then it back to normal light as a feather

Another vote for brakes binding, if you do a search it's been covered loads of times

If you don't have enough free play in the master cylinder push rod then the piston won't return far enough to uncover the reservoir port and the brakes will be held on. If it's the brakes they'll be warm, once they cool they'll free off.

ok sounds interesting i will look in to that
if it is the brakes whats best to do to overcome the problem ?
how do i stop them from binding


thanks guys for taking the time to talk :-)

Make sure there's some play in the master cylinder push rod and if there isn't adjust it.

shall i check that whilst the car is cold or after a run ?
thank you

Doesn't matter. just make sure it has a bit of play.

yes it feels like is has a little play !!

handbrake adjustment too, sounds to me like the brakes are binding back the handbrake off a little too

Check it again after a run. Might just need a mm more.

Small hole at the bottom of the master cylinder under the reservoir partially blocked, so brake fluid cannot return freely. This will hold the rear brakes on until fluid has returned to reservoir.

hi guys well found problem
basically once you apply the footbrake and release your foot off it it doesnt seem to fully retract right out it seems the weight of the pedal just holds a little preasure on the brakes
but if you reach down and pull the brake back with your hand the car moves freely again
what can i do to resolve this ? is it a new brake cylinder or spring behind pedal ?

many thanks guys

lots of cars have brake pedal return springs.

Check there is nothing binding on the pivot or bearing or what ever is used for the pedal.

Every now and then I get grit in the delrin that I have used as a bearing and it stops the pedal from moving freely. Clean it out and the pedal once again becomes free.

A small spring may not hurt but check everything else first.

Adrian