Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Front Caliper - Piston

We are indeed, and somewhat "mild" for the time of year, not really hitting 30 in Perth (yet).

I've done the drivers side today and have the caliper piston's out. Some of the chrome (a small amount) has come off. Wondering if it "matters". Not that I want to be unsafe/take a risk...any thoughts?

Richard, it depends on where the chrome is deteriorating. If it's in the area of contact with the pad or pad shims or in front of the dust cover then I wouldn't worry too much.

If it's in the area behind the dust cover or particularly where the piston enters the bore definitely not as it will probably stick, leak or both.

They're easy to get new and it's possible to get stainless ones too..

I can't remember the caliper model number; M16's were fitted to Plus 8s and from memory were common to Escort Mk1s and Mk2 and Cortinas.

By the way, it is possible to split the caliper; it's how these calipers were converted to accept ventilated discs. Be aware that they are not unknown to leak after being split.

Kevin Vernon's not too far away from me. Interesting what he said about rear discs and I wouldn't despute his logic for road Morgans. I converted my car to read discs as after converting to a Dellorto carburated 3.9, I went through a set of hard compound brake shoes in both practice and race. That's eight sets of shoes just for one event! After three event and twenty four shoes down to the rivets I decided enough. Rear discs pads were not consumed with the same appetite!

Enjoy the tinkering. I'm tinkering with making up some easy-fit race mirrors just in case I get the chance to 'go out to play' again this year.

Here's the damaged piston from the stuck csliper. There is no pitting, but given their importance I have elected to order new ones all round.

Powertrack have come up trumps today!

The wheels are back on and the car off the axle stands. Capilers are cleaned, new brake pads ready, news seals and dust covers too. Just need the pistons now.

Based on the image, replacement's a wise decision.

If you've got good brakes, tires and steering the rest is far less important! If it doesn't start not the end of the world; but if it doesn't stop and stick to the road it might be!

Thanks Richard. I think my agent will go for the Mulfab Hispec 4 piston option with original discs. The question is wether it's wise to change the disc to new ones as well and if ventilated ones offer enough advantages? My 4/4 4-seater is not the most powerful Morgan…….

Greetings, Ruut

One thing to be mindful of with ventilated discs is that the extra weight of the disc increases the unsprung weight of the axle. If you don't compete and generate the heat between the piston, pad and disc, then it's probalbly better to use solid discs.

Ventilated discs might look good and hint at fantastic braking power but if they're hidden behind a wheel and can't impress onlookers and you don't need them, why incur the axtra weight and expense!

With the wire wheels you can see the discs, but it's not to be done to impress onlookers. It's more to do everything in one time. But I can believe that solid discs are probably better for me? Is it wise to swap the old ones for now solid ones, because the discs date from 1990 too!?

I have the Mulfab HiSpec 4-piston calipers on my tuned (170bhp) 4/4, and they give vastly better braking than the standard single-piston calipers, with better feel and better front/rear balance too. No need for fancy discs, the standard ones are well up to the job.

existing discs or new ones. From my experience, Morgans do not cause a lot of disc wear as the car is relatively light. Compare a Morgan with the weight of a Range Rover and you'll understand what I mean.

There are two things to consider: wear and runout. Wear is detectable by a ridge on the outer and inner edges of the disc. If there are 'steps' it's a fair indication of wear and possible replacement. Runout is the amount of 'wobble' or sideways distortion in the disc. Excessive runout causes the pads to 'kick-back' the pistons into the calipers and is generally caused by excessive heat. It's easily detectable by pulsating of the brake pedal under braking or more accurately by placing a guide next to the outer edge of the disc and spinning the disc in situ on the car.

If the wear and runout are slight or undetectable, then save your money for other mods that will improve your car or wellbeing! Malt whisky is a pleasant 'mod' but incompatible with driving!