P38A Rolling road brake test
- Thread starter Wazzajnr
- Start date
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tarphenry
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- bury lancs
NO, if it tries to turn the wheels on 1axle the other axle will try to drag it off the rolling road and damage your car
+1 - not much of a christmas present !
discool
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Engine performance is tested on a single axle rolling road, not brake efficiency.
Brakes are tested on a single split brake test roller. Which won't be used if the vehicle has a limited slip diff.
sassanach
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- trowbridge wiltshire
only if the rollers are set to rotate the front or rear wheels in opposite directions across the axle so only the diff is working not the transfer box.
Cheers guys, thanks for all the replies. Pleased to say she passed with flying colours.
Only thing the tester mentioned was that the back discs are a bit corroded but not bad enough for an advisory. I've got a full set of front and rear pads waiting to be fitted over Christmas hols anyway. Along with new air springs, exhaust system and cats, O2 sensors and then she's ready for the long slog back to Czech republic. (note to self, must also fix cruise control!!!)
Only thing the tester mentioned was that the back discs are a bit corroded but not bad enough for an advisory. I've got a full set of front and rear pads waiting to be fitted over Christmas hols anyway. Along with new air springs, exhaust system and cats, O2 sensors and then she's ready for the long slog back to Czech republic. (note to self, must also fix cruise control!!!)
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- Preston Lancs.
discool
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Or permanent four wheel drive.
You should keep up with the technology.
Even my old RR was tested on a split brake testing roller and that was around 1991 so they been around some time.
My disco brakes have been tested on the same system for the last 16 years.
discool
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Correct. So u know how a split roller works.
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- 58,170
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- Preston Lancs.
Would like to know how they managed the transmission brake.
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- 58,170
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- Preston Lancs.
A P38 must not be brake tested on a two wheel brake tester unless the rear propshaft is removed and the transfer box and gear box are in neutral. Same applies less transfer neutral to Disco 1, Disco 2, Defender and Freelander. Must not be tested on a four wheel rolling road unless ABS and traction control are disabled. A Tapley meter is so much easier.
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All my RR's have been tested on a two wheel roller......one roller goes forward, one roller goes backwards....this way the rotation is only through the axle diff and not through the propshafts to the centre diff or gearbox etc.
For the hand brake, my test centre use an accelerometer in the footwell and going for a drive down the road.
For the hand brake, my test centre use an accelerometer in the footwell and going for a drive down the road.
myfirstl322
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Isn't it a deceleration device?
Last one I laid eyes on was in a nice mahogany case, or was it oak?
Last one I laid eyes on was in a nice mahogany case, or was it oak?
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All well and good, IF your MOT station has that type of rolling road. Not all do, and it is just as easy to do service brake test with Tapley meter when going out the check the transmission brake.
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Mine use the box with the accelerometer. Didn't realise it was called a Tapley meter!
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- Preston Lancs.
myfirstl322
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- Hoots mon...
- Posts
- 58,170
- Location
- Preston Lancs.
myfirstl322
Well-Known Member
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- 41,354
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- Hoots mon...
Brakes come in cardboard boxes, bad brakes means oak casket, or mahogany, or chipboard or cardboard..... na i'm not sure where i'm going with this either tbh.
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