8 replies to this topic

[lippo]

 It's been quite a week for the Mini, rolling road last Thursday which I'll post about soon. I did notice on the 50 mile drive to RE Performance in Bury that the car dips to the right when the brakes are applied. If I lift off and immediately re-apply the brakes the car goes straight. If I leave it for a short time, the slight swerve to the right occurs again.

 

 I checked the subframe movement when turning the steering wheel. There is definite movement, about 1-2mm. I've checked the floor mounts, the nearside has a small amount of movement. The teardrops both move slightly too.

 

 The subframe appears new, or at least in excellent conditions. The floor mounts look new too and all mounts are rubber.

 

 My question is, is any movement unacceptable, or is there a little bit of tolerance?

[absx2]

Having tear drop mounts that tells me you have a single bolt rubber mounted subframe, well in standard form anyway.

With the rubber mounts if you move the steering wheel from side to side with your arm through the window whilst looking into the engine bay you will see a hell of a lot more than 1-2 mm generally which is why solid mounting with alloy ( not poly ) is a good move for car that is to be driven hard through the bends.

 

As for the braking it could be soft tie bar rubbers or a little brake imbalance including the rears that can cause the car to pull a bit initially assuming that your suspension components and radius arms are in top condition.

My own car had a bit of a heavy braking weave last week that turned out to be a little too much braking on the rear that was quickly solved by turning the adjustable brake bias valve ( MS72 )

[lippo]

 Thanks for the reply. 

 

 The suspension is new hi-lo's all round, all the suspension components look new. I've cursorily checked the front brakes and they seem fine. I haven't checked the rears yet but I've bought the square spanner from Minispares to adjustment them correctly. I need to check that everything is tightened up right, and the car could do with a 4 wheel alignment for my peace of mind.

 

 As for the movement, this appears to be standard for the rubber mounts? I would go solid but I'm not after ultimate racing spec, I want a car that runs well, goes straight and stops when required. I would be nervous about putting the solid mounts on a 45 year old body.

[68+86auto]

I don't believe your problem is subframe movement.

[Lplus]

I don't believe your problem is subframe movement.

I tend to agree, it wouldn't change just because the brakes had just been applied.  I would be looking for a slightly tight brake on the rhs which acts more effectively at first due to being slightly warm from rubbing, but which is equalled by the other side when both have been warmed by braking.

[andyapanel]

If it was my car, my first thought would be brake piston corrosion, not subframe movement.

 

Jack the car up, take the front wheels off and apply the brakes, then release them.Look/feel for one of the pistons not releasing effectively.

 

It might also be a faulty/rusty lever in the rear hub assembly.

 

Good luck

[lippo]

 Thanks all. I'm reassured it's not the subframe mounts, they all look new. I was going to investigate the brakes today, but instead spent it dropping the tank and replacing the fuel gauge sender unit.

 

 I will test the front brakes during the week. Thanks again!

[coopertaz]

sticking front caliper?

[lippo]

I don't believe your problem is subframe movement.

 You were right. One front and one rear original brake hose had swollen inside, restricting the fluid to the caliper/cylinder. All new hoses fitted and the car stops in a straight line.