Brakes

[LRTR]

The brakes on my spitfire are useless and I can't work out why. The Spitfire has been completely rebuilt and part of this was a brake system overhaul. Almost everything was replaced, all new brake pipes and hoses, the calipers were rebuilt with new seals and one had new pistons, there are new discs and pads, the drums had new cylinders and the master cylinder has new seals. The only things that weren't changed are the brake shoes as they still had a lot of friction material on them and the major units themselves like master cylinder, calipers and drums etc.

The system was incredibly difficult to bleed even though almost everything was new, it has got to the point where they are usable but I'm still not happy with them, I know they can be much better.  

Any ideas of possible problem areas?

Cheers
Matt

[Nick Jones]

Do you mean pedal feel/travel or pedal effort?  

If pedal effort:
What are you comparing them to?  They'll always take a fairly hefty shove compared to a modern with servo.

Otherwise, are the caliper pistons moving smoothly and easily?  What are the brake pads?  Some of the current "standard" ones appear to be made of greased cardboard and seem incapable of producing any real friction.  Use something decent like Mintex 1144 and the "bite" reappears as if by magic!

If pedal travel:

What methods are you using to bleed?  Some of the "one man" type devices are a bit crap although I've always found small chassis brakes easy to bleed.  Presumably the flexihoses are new?  A dodgy hose can cause a long pedal travel - you can try clamping each one off in tu=rn and seeing if it makes a difference.

Good luck

Nick

[LRTR]

I'm comparing to a mates non servo MGB GT, they have bigger brakes but are a heavier car, that pulls up well without too much effort (for a car of it's age). The Spitfire has alot more pedal travel before anything happens, with the MG you touch the pedal and it is solid, it isn't like that with the Spitfire.

The brake pads are standard but are NOS judging by the box they came in. I don't know if the pistons are moving smoothly, I will check.

Bleeding was done with the standard two man method, I do have an easibleed but not the correct size cap for the Spitfire although we did try using the easibleed in reverse to see if it mae any difference (connecting the easibleed to the bleed nipple and using the air supply to force fluid through and the air to the master cylinder). A vacuum bleeder would be better but i haven't got one of those yet.

The flexi hoses are new, we had one with a hole in it from new but that was replaced.

Cheers
Matt

[CHRIS211083]

Adjust your rear brakes. This will sort your problem or you need to bleed them again. Jack up the rear of the car. Spin wheel slowly with hand and tighten rear adjuster (square lug at bottom of back plate)until slight friction is felt. Then turn the adjuster back one click. Move to the other side. This is the most likely cause of excessive brake pedal movement. Give it a go and test then bleed it just for extra bite. I have standard brakes with flexi hosees and standard pads too and they stop very well indeed. If all else fails take it to a garage to bleed or buy the pressure bleed kit. Let us know how you get on. Chris.

[Clive]

Rear brake adjustment is indeed often the problem. Some people (and garages!!) adjust them on th ehandbrake cable. This is plain wrong. I wouold suggest releasing the handbrake cable, slacken off the drum adjuster (the square on on the backplate) and remove the drums. Check the lining, then replace drums after a clean out, and adjust them up BEFORE reconnecting and adjusting the handbrake cable. This can make a huge difference, as the forst bit of pedal travel can be used to get the shoes up to the drums before any braking will take place. Not good.

[Doug Paterson]

Agree with all the above and would add one thought from my experience.

I fitted brand new disks/pads/drums a few years back and was distressed to find the (correctly adjusted  :) ) brakes were rubbish.

Standing on the pedal with all my might could not lock the wheels.

Replacing the standard £7 from Rimmers pads with Mintex Racing M1144 pads had the car braking fabulously.

Some years later I changed the generic shoes on the rear for better material which gave a discernable improvement also.  

D.

[Nick Jones]

Yes, cannot empasise enough how rubbish some of the current "standard" pads are.  They are just using compounds intended for modern cars with servos and the non servo system just cannot apply enough pressure.

Nick