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MG MGA - Brake and clutch pedals
|If I press my brake pedal, on its release it returns without problem. But if the clutch pedal is also pressed, if I relese the brake pedal before the clutch, the brake pedal returns virtually the full way, but not completely. When I subsequently release the clutch pedal, the brake pedal returns completely.|
Its a 1600 Mk2 and so they share a single master cylinder and clearly it is either friction of some sort between the pedals at the fulcrum, or something inside the master cylinder. It seems like the former (or maybe that's me just being hopeful!) as the brake pedal returns if I just "wiggle" the depressed clutch pedal.
I was wondering if anyone has ever had this problem? Should I put a little grease between the two pedals at the point they rub? Thanks.
|Some years ago, my brake and clutch pedals also where behaving strange. Not binding, merely wiggling and not always doing what I wanted them to do.|
It turned out that the nut securing the bolt on which they both pivot came off, and the bolt slid out a bit. (The bolt is inside the rubber booth in the motor compartment, where the pedals are attached to the push-rods, so you canít see it without loosening the rubber part.)
I can imagine that a situation like this can cause several problems, also binding.
After greasing it all a bit, while I was there, and putting a new locknut on, it was fine again.
Maybe worth a check ?
|Rik de Krom|
|Nice one Graham|
Ican not imagine anything in the MC could possible cause anything such as this.
What must be remembered is that as the pedals are released the effort applied by the springs and the hydraulic fluid is at its lowest when they are nearing the top of their travel. So it follows that if there is any friction at all it will manifest itself at the fully released point.
As you already know the way to sort this is to sort out the interference between the pedals around the pivot. Happy lubricating :)
|Robert (Bob) Midget Turbo|
|Thanks for the help. Reassuring to hear its unlikely to be the m/c. Bob I know that you are keen for me to get on with lubrication but looking at the exploded diagram, I see there should be a washer between the pedals, which I cant see on mine. Over the next few days will take off the rubber boot, etc and take a proper look.|
|Graham M V|
My pedal pivot had washers missing and also a non locking nut on the pivot bolt. After removal, cleaning and lubricating, I fitted washers between all 4 moving pedal surfaces (If i recall, i had to reduce the thickness of the spacer) plus under the bolt and nut, nipped it up enough to take out excess slack AND used a nyloc nut. The last thing i wanted was the possibility of the nut working loose (or indeed 'processioning' and tightening up as the items might turn slighty in use) out of sight underneath the rubber seal.
|Colin, the main pivot bolt for the pedals should not be subject to rotation at all. It should be tight in the pedal mount, with no slack between the spacer and the inner bushings. Tightened up, the pedals should still swing freely because the inner bushings are longer than the outer bushings. By reducing the thickness of the spacer, you have probably ensured that the pedals will not swing when the bolt is tightened up properly, and if it is left loose it will cause the holes in the mount to wear, because they are not supposed to be subject to motion of the bolt. If driven this way for long, you'll have to repair or replace the pedal mount, as well as the spacer and bolt.|
|If clutch pedal operation has any effect at all on brake pedal operation (or vice versa), the thrust washer between the pedals may be missing, or the pivot bolt may not be tight. There should be two steel tube spacers serving as bearing journals for the bronze bushings, and three steel thrust washers. All should be pulled up tight with the pivot bolt and locking nut so none of the steel tubes or washers can move. See here: http://mgaguru.com/mgtech/hydraulics/ht110a.htm|
This thread was discussed between 21/07/2010 and 22/07/2010
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