Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Brakes

I've a series 2 4/4, having bled brakes the left front wheel developed a tendency to lock up. I changed master cylinder, re-bled and changed front hoses, no difference.

Yesterday I removed both front hubs, bearings etc in very good condition (recent as in 10 years, renovation), but there were 4 newish looking girling cylinders, each had brake fluid coming out, just a small amount. Pads on right upper were glazed.

So I cleaned her up, cleaned cylinders, and a little better but still locks up.

I've ordered 4 x new girling cylinders to replace this week, a new master cylinder again (not convinced on the one I was given with car) and a new rear brake line.

All spirngs are good inside the brakes, all mechanisms seem to be working fine.

I've bled it about 10 times (properly with both foot/helper method and vaccum pressure system) so not sure if a stubborn bubble in the metal line from right to left front brake.

I've not gone near the rears as yet.

The cylinders are cheap enough to replace, so sensible, but any thoughts?

Send your old cylinders to Past Parts to have them bored and stainless sleeve fitting - will save the regular replacement of cylinders in the future.

Just bought new ones, for all they cost £120. Front shoes are fine but I'm struggling to find any replacements other than linings

Check that the leading edge of each shoe has a chamfer on it. This should stop the shoes grabbing and causing lock up. Maybe earlier after market replacements didn't have this chamfer.

I'm with Graham here, my 2010 plus 4 has the cylinders stainless lined from past parts, Bought new cylinders and sent them straight there. Before this my cylinders seized over winter every year, now since 2022 they have worked perfectly and the standard cylinder repair kits fit the lined cylinders so any wear and its just a quick service at £12 per side although as yet I haven't needed to carry this out. Now, I service my car diligently and change my brake fluid annually. Check moisture content throughout the year yet still the cylinders would gum up without fail. so my advice to any classic owner would be to line the cylinders! First used on racing cars for its bomb proof reliability they really do help.

Not sure what brake distribution system you have fitted but try a back bleed through each cylinder nipple to see if you can get some flow. If all ok then i'd suspect your mechanical side. Shoe friction material thicknesses, spring strength, shoe retaining locators and lubrication against back plate. Something is locking them up when fully applied then released. Just use a rubber or nylon mallet to tap the shoes from side to side at each cylinder. As you move one across the other side should move out the same amount and then back again, this should move easily with little resistance and good cylinders will move with hand pressure even when fully assembled. If they don't I reckon the cylinders are gummed up. I have written previous posts on how to rectify this but come back if you find a problem with this.

Just as an aside, when I first got my Mog I drove it for the first few months when clearly the rear cylinders were seized and no brake effort was being delivered to either rear wheel....... car performed fine, however when I rectified this, (I quickly took the car off the road for a major work-over as so many things were just frankly blooody awful!) I have to say I could not feel any improved breaking effort or flatness in the brake feel. The only thing that has changed is, if breaking hard in the wet the back end can twitch a bit, although not unmanageable, mind you a 1990's Golf Gti makes anything feel good in the wet when being compared with it!

The Morgan set up is really quite primitive and a methodical approach will soon get you sorted out. Just one last thing. I have come across cylinders that look like they are leaking just a little but its been the lubrication applied to the piston seals and often the excess amount stuffed under the dust covers trying to stop them seizing that is wet. I'm starting to believe that some of the lubricants that are used might be the cause of this gumming up and have reverted to the old school use of brake fluid as a lubricant on assembly and then a very small amount of red rubber grease to the lips of the dust cover (both cylinder and piston) which seems to be quite effective in keeping water at bay but not causing harm. I'm sure many here will come up with a suggestion as to which assembly product to use but I have to say I started working on cars from the end of the 60's and I have never seen as many wheel cylinder problems since all these new fangled brake lubricants have been foisted on the market.... I'm coming around to the ... if it aint broke mentality here!

That's really helpful!

Firstly the front edge of the shoe is angled, so that seems fine, one side (not pulling) is glazed, so I sanded off). The cylinders (ordered replacements) all have a little liquid but all move freely.

The shoes look ok - if anyone can advise on replacements, I can't find them at all, but have enough "meat" for now. Any help he greatly appreciated.

Back all bleeds fine, I don't think an air bubble as I've bled a lot.

The cylinders were wet with fluid a bit, I took the caps off and cleaned up a bit, just looked like a small weep, dirty fluid, not fresh.

The grab started when I bled them and then installed day after a new master. I ordered another master as I suspect this one is not right, but dont think that would impact left brake only.

Wheel locks up at light touch if adjusters turned CW, so definitely grabbing and holding. Inside of drum looks fine to me, cleaned that too, no contamination.

Springs are strong, adjusters work fine.

I did notice the shoes dont seem to sit right left and right, one side sticks out, but given working fine when I bought, and shoes I think are correct, only started later. At first when I got it a 100 miles ago the right slightly pulled, now shifted left after bleeding the dirty fluid out. Front brakes lines made no difference at all. When I turned adjusters it made it worse, maybe alignment of pad.

Might be wrong but that shoe/spring setup doesn't look right and certainly not symmetrical. See below image from 1953 plus 4.

That one is the same as my OSF, it was very helpful before. However his bottom show is slightly different, that one doesn't pull, so I think shoes, spings are ok. It only happened after I bled, and I've bled many times over the past week, with other person and solo. It improves slightly after bleeding then goes back. I think the left shoes grip immediately and dont give, so maybe an air bubble in the crossover or pads grabbing, but only variable really was the use after bleeding.

I've ordered a set on plus 4 pads which look similar but could be winder I'm not sure. At £50 it was worth a punt, although these shoes look fine.

I think we need Arwyn Williams for this one

But just a quick one to try, after applying the brakes & if they stay locked - try releasing the brake pipe out of the master cylinder to deliberately make it leak, if the brakes release, you have a faulty master (not unknown to happen)

Importat I forgot to mention, it doesnt lock up in reverse