Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Plus 4 brake callipers

Last MOT the brake test showed significant imbalance of the front brakes. My tester is a good chap so I asked him to take it for a drive and try the brakes which he did and agreed with me that the car brakes straight and true. They continued to perform fine all season.

I’m about to start my annual ‘pre MOT service and check’ and I intend to have a look at the possibility of a sticky piston

I’m wondering if anyone has experienced a similar scenario and if so what solutions did you employ?

It’s a 2012 plus 4 with standard brakes all round. Very low mileage of just 8K so likely to still be on original pads with lots of life left. I may change them anyway so what do folk recommend?

Thanks

Gary

Does your MOT station use rollers or plates for the brake test? I used to go to a place that used plates, and the narrow track of my 4/4 always gave problems as it couldn't be centred on the plates. A few times they took it out on the road with one of those inertia hobbies in the passenger footwell to get a proper reason.

Nowadays it goes to a station with rollers and there's no problem.

As for brake pads, I use EBC greens, they are fine.

Rollers

Which pads exactly? I was intending to replace them with Mintex MLB52, I think they’re the correct pads?

Hi, Grumpy2

Caparo calipers are fine and a fairly good product and certainly adequate for a sub 1000kg car even though the plus 4 is slightly heavier. Roller MOT stations are the norm now and really aren't suitable for the Morgan classic as the car simply isn't heavy enough. Local authority MOT test centre's should have a decelerometer tool which sits on the front seat and assess brake efficiency. They should be able to test classic cars of all types, imagine trying to assess a model T ford on rollers! If you struggle to have the brakes checked properly it really is worth finding someone who knows what they are doing. There is a web site for classic car servicing and you should be able to source someone close to you through that site

Now, your car is pulling up straight and satisfactorily and the tester found their functionality in use correct, so from that I would think they are working correctly within the parameters of your cars needs. One problem the Mog suffers from badly when fitted with front discs is they just don't create enough braking force to wear/clean the disc's and if for road use, as lots do, fit racing type pads or upgraded pads they lose what little effect they had in abrading the disc surface and keeping them clean. Here's the next thing, and you'll know this anyway! The grease splatter from the front suspension gets everywhere and some does find its way onto the disc's. Have you ever seen a Morgan classic with bright shinny clean disc's.... I'll bet not! So, the discs and pads smear this grease onto their surfaces which effects the braking efficiency. I have found that every couple of years one has to tackle the issue and for me this means removing the pads and then the calipers cleaning them thoroughly in brake and clutch cleaner and the same with the disc surfaces. Now this won't fix it totally. When the pads have fully dried, and you may have to do this 2 or 3 times before moving forward I recut a surface on the pad to remove the glaze. 320 grade carbide sanding paper on a flat surface, granite work surface or similar, and with a firm downward central pressure make a couple of 6" sweeps to each pad. Inspect and repeat until de-glazed. To the disc surface I do similarly but with wet and dry and wetted with WD40. Use small circular motions and continue around both inner and outer surfaces until you are happy that any glazing has been removed. Then clean again using brake cleaner. Once fully dry I then use dry paper and repeat the process, It's a little like de-glazing or honing an engine cylinder.

If your calipers are working fine then there is no need to disconnect them from the hydraulic line but do use a brake caliper wind back tool or a suitably sized piece of wood to prevent the cylinders working their way out and giving you another job to do!

Also, how's your brake fluid? has it been changed, checked for water content! It's hydroscopic so absorbs water and this is held throughout the total volume of the fluid, when you brake, the calipers get hot and water boils thus creating steam and a gas in the system reduces efficiency, quite a lot! This is why a brake fluid change is recommended avery 2 years regardless of mileage. Looks good, might not be! You can get the water content measured or buy a simple tool to do it yourself.

Lastly, a disclaimer! It is not recommended that procedures to braking surfaces like I have just explained are carried out, rather that they should be changed for new parts, especially if contaminated but, the Mog is a car designed from the mid 30's and the plus 4 from the 50's and cleaning brakes in this way was then a common practice. You don't find anyone greasing up the front suspension of their modern daily driver today! So that contamination issue has disappeared. It is not a procedure that can be undertaken year on year, just perhaps a couple of times in the brake pads life on the car and then they will be changed long before they are worn out.
When you do change them look for a softer pad for road use as this will increase brake efficiency as well as keep the disc's cleaner! Anything involving safety on a car and especially the braking system should not be messed with if you are unsure of what you are doing in which case you should seek professional help.

As the suspension needs regular greasing for effective operation, make that procedure a part of cleaning the splattered grease up and this will go a long way in helping braking function. Remote suspension greasing is in my personal opinion is a huge problem as you cannot really see what you are doing and if you can't see what you are doing you are certainly not in a position to clean the excess grease away and guess where it will end up! Not trying to teach granny here G2 but if others are reading this it will hopefully have some benefit for them.

I use the EBC 285 Green Stuff pads in Billet 4 pattern as I have the Hi Spec aftermarket 4-pot calipers on my car. You want something as soft as possible really for road use, Morgan brakes never get anything like hot enough to warrant track pads.

Typical of low mileage cars. I would simply remove the pads and put in their place a piece of wood or a few bits of hardboard just a bit thicker than the pad backplate. Then stamp on the brake pedal a few times. A good squirt of brake cleaner over the now exposed pistons, then gently push them back in place enough to re insert pads.
I wouldn’t waste money on new pads; I only changed mine at 50k and there was still plenty left on them.

Don't forget about the lip of unworn pad material you sometimes get on the outside edge of the pad!

Just visible here...............

thanks for all the above tips

I've tried contacting Mintex and they're no help at all saying they don't manufacture a suitable pad - even though Wolf list several (M1144 possibly suitable?)

I've been using my chap for over 30 years - new cars and considerably older ones than the Morgan - he's a good guy. Thanks why he took the car out with his decelerometer and agreed the brakes pull up straight and true.

Agree entirely about grease and brakes - they get an annual cleaning as part of my servicing routine. And the pads are moved and pistons pushed out and back in. Brake fluid change due this year - done two years ago

cheers

Gary

Mulfab supplied Mintex MGB522 pads with my Hi Spec disc and caliper upgrade kit. I could not get on with them at all. I'm a very light braker and could not get heat into them, so initial braking was a lottery. They didn't bite well, and fluttered side to side. On the MoT rollers they were only just a pass. So I reverted to Greenstuff, accepting that they are a Marmite pad. They suit my light braking style.