Squeaky Brakes

[politeperson]

I never have had much of a hand brake, not too bothered living on the Fens. Now I think I know why it doesnt work!

At low speeds I have always noticed a bit of noise coming from the rear brakes.

Apply the handbrake and the noise almost disappears.

Over the last couple of days it got pretty noisy, so I took the car up to my friendly Mercedes Garage a few hours ago. They stuck it on the lift and we had a look with a torch.

Well, 3,000 miles ago I had 4 handbrake pads. Now I have 3.1!

One was worn down completely. The rest like new. Picture below for comparison.



The question is why? Cant say I have touched them, they have been on and off, but cant say I have given them much thought.

As it was 5.15pm and the Mercedes garage didn't have any Jaguar pads, Nigel unbolted the two bolt /pins holding the RHS handbrake mechanism on, undid the split pin and we removed the whole unit in a couple of minutes from underneath.

Nice quiet drive home, albeit with no hand brake.

I must admit, I didn't even think about the fact the handbrake calipers might have a ratchet mechanism inside, when I dropped the IRS and did everything else. Seems it might seize up on a 50 year old car.

So I removed the case and had a look, revealing the ratchet mechanism, all in lovely unworn condition but caked in dry grease.




So, I shall clean it up and re grease it after I have purloined new pads. I shall lubricate the other one with grease as well.

I am just not quite clear to me what the mechanism is that pulls the pads away from the disc.

I did notice that a small pin was missing from the hole to the bottom of this picture in one caliper half. I think it must lock the adjusting screw. Maybe that was the issue? The pin was missing all along?

[kingzetts]

The handbrake pads are held off the disc by the brass fork which is held in place under the pivot bolts which retain the pad carriers to the caliper casting. The two ends of the fork then locate in small holes at the opposite ends of the pad carriers forcing them apart and off the disc. I once had an issue where the end of one fork was not in its hole but instead was pressing the pad against the disc. Over time this wore away that pad completely and wore a groove in the pad carrier as well as wearing away the edge of the brake disc

[christopher storey]

Note also that the self adjusting ratchet system will not work if the split pin ( or R clip ) is missing at the screwhead end of the ratchet shaft. If it is missing, each time the pawl engages it merely turns the shaft and does not in effect screw itself along the shaft

Also, getting the bronze forks into the holes in the pad carriers can be a fiddly job, and they have a tendency to come out again while you are reassembling the whole apparatus with the shouldered screw in pins

[MarekH]

Dear James,

There is plenty of information on another (older) thread about upgrading the handbrake mechanism either by letting the lever mechanism float when the handbrake is applied or by altering the distance that the clevis pin sits from the rest of the mechanism. Either method will make the handbrake pull on both sides equally and prevent a recurrence of your problem, once you have serviced and restored your handbrake mechanism.

kind regards
Marek

[politeperson]

Thanks boys.

As it happens, I found oil all over one of the rear discs and got a wiff of petrol from the same area.

So the whole thing is now in bits.

The tank wasn't too bad when I took it out. It has been now brazed in one area, so I will refit it tomorrow or Wednesday.

The output oil seals are on there way, so I hope to button the whole lot up by Wednesday evening.

I will pay special attention to the flaming handbrake mechanism this time!

By the way, my radius arm bushes, fitted in 2016, were knackered completely. So I have boought the expensive ones this time.

[mgcjag]

Hi James...a modification to the handbrake mechanism that is well worth doing quite simple to do and well documented here on the forum.... just cut through the rod connecting the mechanism to the bracket and weld on a tube..it allows the mechanism to slide when you apply the handbrake and applies even pressure to both sides

[politeperson]

Thanks Steve, I will definitely give it a go.

[politeperson]

Just to finish this thread, I got everything back together today and all is well.