little help and advise please on my classic p4

[400+bhp]

having failed its mot on steering and bushes and king pin and brakes, we have now replaced all the bits etc how ever had 2 re tests and it fails on the hand brake efficiency each time ?? have been told that they put it on the rollers and it should be 25% min to pass on their dials ??? is this not for the newer cars and not the classics, any views as we are starting to pull our hair out.. as a reminder mine is a 58 rover 90 p4 for the record all the brakes have new shoes and the hand brake lever feels right and is really yanked up... so many rods under the car to adjust my concern is are the mot testers trying to get the impossible from this car due to design etc etc thanks all

[Slade Alive]

Call and ask VOSA

[jith]

400+bhp said:

having failed its mot on steering and bushes and king pin and brakes, we have now replaced all the bits etc how ever had 2 re tests and it fails on the hand brake efficiency each time ?? have been told that they put it on the rollers and it should be 25% min to pass on their dials ??? is this not for the newer cars and not the classics, any views as we are starting to pull our hair out.. as a reminder mine is a 58 rover 90 p4 for the record all the brakes have new shoes and the hand brake lever feels right and is really yanked up... so many rods under the car to adjust my concern is are the mot testers trying to get the impossible from this car due to design etc etc thanks all

Dear me 400, you're serving your time on this one!

When the MOT was done on these cars years ago, they used a device called a Taplin Decelerometer that sat on the passenger floor. You simply applied the handbrake at around 20 MPH and it gave a reading due to a pendulum situated in the body of the device: the more powerful the braking effect, the further the pendulum swung.

It sounds crude, but it was actually quite accurate because it tested the car at speed on the road, and therefore measured the braking system's ability to cope with the inertia of the vehicle. You can also get an erroneous reading on a rolling road from cross ply tyres, particularly if the pressures are not spot on. Does the handbrake slow the vehicle down if you apply it at speed? Does it hold it on an incline?

When the Rover's handbrake system is properly set up it should be tremendous, because you have massive rear drums, a solid linkage system and tremendous leverage due to the length of the handbrake lever itself. The only problems I ever encountered with these was seizure from lack of use or salt ingress on the linkages.

What you must do is ensure the shoes are properly adjusted before adjusting the free play in the linkage, not the other way around. It could be that is the problem.

[ARH]

single circuit brakes requirre 25% and duel cicuit brakes requirre 16%. If set up correctly it should pass. if not get them to test it with the tapley meter as mentioned earlier, they should have one as not all cars can be tested on the rollers.