MOT Failure - Foot brake 'efficiency'

[Harley Dave]

Caffyns of Eastbourne - may not send to HK though

https://www.ebay.co.uk/str/caffynsvolvoparts

Cheers

Dave

[drjarmin]

Originally Posted by Harley Dave

Caffyns of Eastbourne - may not send to HK though

https://www.ebay.co.uk/str/caffynsvolvoparts

Cheers

Dave

Thanks. I I'll try that. I have a freight forwarding agent in the UK. Only downside is I can't save tbe 20% VAT

[S60D5-185]

I have had excellent service from this outlet on Ebay.


https://www.ebay.co.uk/usr/volvopart...p2047675.l2559

[drjarmin]

Thanks. Good to have an alternate at least until FRF start trading again.

[spiralarms]

If you are maintaining your car yourself, how do you check the parking/emergency efficiency?

To do the road brake test, I believe they use some sort of decelerometer. Given that mobile phones have all sorts of sensors, I thought I'd find "an app for that", but failed. Instead I did find one that just records the 3 accelerometers and then stuck the output of that into Excel. Fortunately we live on a mostly flat, straight country road, so got the car up to 20mph, and then stamped on the parking brake. The attached graph shows my results.

The grey "mazda" line is just for comparison with our little Mazda 2. Time in seconds on the X axis, and some measure of acceleration in the Y (perhaps in "G"). I didn't suppose the units really matter, as long as I can see an improvement before and after adjusting the brakes.

Volvo 1 and 2 are two runs before any fiddling (and just after the MOT fail), one would be slightly up hill, the other slightly down. And shows that it look between about 5.2s and 6s to stop the car.

Volvo 3 to 6 are after some adjusting, and all within 2mins or so. And that shows the brake now stops the car between 4.5s and 5.5s. If I choose to ignore that Volvo 6 (5.5s) as it was slightly downhill and by now the brakes would be rather hot, then down to between 4.5s and 4.8s. Which is better than I started off with.

I just need to replace an track rod end, and then I'll be taking the car back for another MOT, then I'll find out how my results translate into "parking efficency".

Anyway back to my original question, how do others measure their braking efficiency? Do you just go and buy an expensive gadget?

Neil

[S60D5-185]

No, I simply pull up to a halt on a steep hill and apply the parking brake with the car in neutral.

No fancy equipment needed, it should be very obvious if it is working correctly. 👍

[tonygreen1966]

Does anybody know there was a way we could equate the 15% efficiency(or whatever it is the MOT requires) to a torque and then apply that to the wheels with a torque wrench for a 'rough check'. I'm pretty sure my XC90 has failed in the past due to one wheel not having a good handbrake effort.

[spiralarms]

I wondered about that too, before I tried the app thing. I dare say you could work it out, you know the weight of the car, distance of nut from hub (if that's even relevant, Higher grade physics is a long and distant memory). Certainly before my adjusting of the brakes, I couldn't loosen or fully tighten the wheel nuts with the wheel off the ground. Now I can.

As for S60D5-185 and parking it on a hill. I would if we had one close to the house, and I knew what slope it was. I would. I guess you need a 17% (about a 1 in 5) slope to try it on.

Neil

[gmonag]

Just try pulling away with the parking brake applied. You can tell if it is working efficiently or not.

[john langrick]

And also note frf Swansea is up and working.

For me the last part ordered last week arrived with two days and a decent discount as a forum member.

Thumbs up from me..