Porsche Enthusiasts Club Forum

A failure on my 944 today was the parking brake efficiency. I asked the tester which side was the problem and he said he didn't know because he used the Decelerometer Test to test the parking brake.

I didn't question it at the time but when driving back I thought why on earth would you use the Decelerometer Test to test the parking brake instead of the rollers? They used the rollers last year and there's no reason why you can't use the rollers on a 944 is there?

Im an mot tester and I would take it back and ask for it to be done correctly using the rolling road,This will also show which side has failed and what efficiency..The Decelerometer test is for 4x4 or perminent 4wd vehicles.

Maybe he thought your car had an LSD. This is a can of worms now but some people get funny about testing a car on the rollers with an LSD due to potential damage. How low is your car? Some testers will refuse to test very low cars IME but some will but use a decellerometer if they are worried about damaging the car when putting it onto the rollers.

Either that or his rollers were not working great...

On another note I believe the brake test has now changed ; instead of the machine giving an imbalance figure a VTS device now does it for them upon then entering the figures.

My car is standard height. I don't want to rock the boat and they refuse to retest it but once it's got a fresh ticket I will ask for the reasons.

As far as I'm aware it doesn't have an LSD, but i guess it would be a bonus if it did!!

He did say it was only just a failure so it won't do it any harm adjusting the handbrake though it does feel ok as it is.

I have used the test centre for over 10 years and never had an issue with them though the tester today was someone I'd never seen before.

A good tip for the 944 type parking brake is to gently pull up the handbrake while driving to the station...These are only parking brakes and so get no real friction/use against the shoes/drums in normal use. A few gentle pulls only enough for the shoes to bite with finger firmly holding down the release button so as not to fully engage the brake should give them a new lease of life assuming that they are generally in good health anyway.

Pete

I agree with Pete, give them a grind on the way to the mot

Hi

They wont run my 928 on the rollers for a handbrake test as it does have an LSD...

Either yours does or they "think" it does....

And yes it can damage an LSD ...

All the best Brett

I will check for an LSD when I get its backside in the air later in the week to do the handbrake adjustment.

I just assumed it didn't have one!

If it has M220 on the sticker that's for a LSD

Not unheard of for the gearbox to be swapped though. Just get both wheels off the ground turn one and see if the other one rotates in the same direction.

Thats the plan

or see if it initially turns slightly and then becomes tough to turn. My Turbo was like this as were other plate diffs/viscous coupled differentials.

Went for retest today and passed with no advisories. Handbrake check was on the rollers. Can use the thing now