Rear brake proportioner valve pipe kit

[Lotussi]

Hi there,
My Elan does not brake enough for MOT ( in Germany)
I purchased a Elan M100 Brake proportioner valve pipe kit
PNMJ6049K
After installing not enough brake force at rear brake.
Does anyone have experience with this?

[TorqueHorse]

They make these adjustable ones that might help you dial it up until it passes.
https://www.wilwood.com/MasterCylinders ... =260-12627

[Denny]

Apologies if stating the obvious or if you have already checked, but are the rear caliper's, sliding pins etc. OK and not sticking?
I have just had new proportional valves and the original caliper's refurbished and they passed the UK MOT with ease.

[dapinky]

If the OE proportioning valves are good, but the rear brakes still don't have enough movement to pass the test, then the issue is probably with the rear callipers (or possibly, but unlikely, the master cylinder).

Although I am an advocate of fitting the adjustable valves, I would not see it as a simple way to pass the TUV test.... it may well allow the car to pass, but only by forcing more pressure to the rear than will give a balanced brake system. It works great to fine-tune a system where other parts are non-original, BUT the first thing to do before setting them is to ensure that all 4 callipers are working perfectly.

[RonR]

Si,

Are your front brakes upgraded (PNM, HiSpec, etc), and does the TUV test use a percentage Front / Rear to calculate a pass or fail?
It could be that your rear brakes are working perfectly but if you have upgraded brakes on the front of the car it's skewing the balance.

[Lotussi]

Thank you all for your answers,
I have passed them all to the garage - I will let you know the outcome

[simonbuk]

Any further updates on this ?

[Lotussi]

Hi, no....
I went to the garage again and told them about all the different answers you have all given me, thank you, so far no luck
They have some old school mechanic coming in next Friday, maybe he has an idea.