Rear end skittish under heavy braking..

[Tunst]

As the title says really back end seems to move about alot under heavy braking.. Quite un-nerving at times

It has some shocks on the back which arnt standard items so im wondering if that could be the problem?

Its a 182 cup so could have been fitted with basic 172/182 rear shocks rather than cup items? Those will be he next this i replace...

 

[Cup_Phil]

It's usually rear brakes coming on too hard
Could be your brake compensator valve?

 

[Tunst]

I thought that but i looked and cant see one haha

 

[Tunst]

Nope no compensator.. I think its just te 172 cup that had them?

 

[MarkCup]

Nope. 172 Cups are the models the don't have them...yours should have one as far as I'm aware.

Lack of valve will explain the issue your having.

Find a 172 Cup owner that's been convinced they need one by a clueless MOT tester and buy it from them!?

 

[Dan@SJM]

The non cup variants brake bias is controlled by the ABS module so it won't be that.

 

[Dan519]

Nope. 172 Cups are the models the don't have them...yours should have one as far as I'm aware.

Lack of valve will explain the issue your having.

Find a Cup owner that's been convinced they need one by a clueless MOT tester and buy it from them!?

nope. 172 cup is the only model that DOES have a compensator. It's just fixed in one position rather than with a lever rod on it

All models with ABS use the ABS unit to control brake balance.
I'd check your calipers are working properly, I saw 3 in one day this week with sticky rears because of the cold

 

[mark123]

Probably shocks.

 

[MarkCup]

nope. 172 cup is the only model that DOES have a compensator. It's just fixed in one position rather than with a lever rod on it

All models with ABS use the ABS unit to control brake balance.
I'd check your calipers are working properly, I saw 3 in one day this week with sticky rears

Right-o, my mistake.

 

[Cup_Phil]

Ahh yeah non-cup so yours is ABS controlled - as Dan has said I'd check they're freed up. The rear calipers are a s**t design in my opinion, they seize up quite easily.

Just jack one rear corner up and see if they spin freely
Could be the shocks - but they'd have to be VERY wrong to make the back end squirm under braking. Does it feel ok on corners normally when you're not braking?

 

[Tunst]

Rear calipers are fine not sticking etc so thats why i put it down to the shocks..

 

[markkram]

I'd suggest shocks. Mine was very lively on the rear end under heavy breaking and after checking everything on the braking system was OK decided to replace the shocks. They were fine to look at no leaks etc but at 60k guess they were just a bit tired. New shocks fitted and the rear end is now very stable.