Talk Morgan Forums Thread Like Summary - Brakes

My 2012 plus 4 stops very well on the road

When the MOT man puts it on his tester however the front brakes are always quite imbalanced, there’s about 30% difference between left and right. Yet on the road it pulls up straight and true.

My yearly maintenance involves removing both calipers from the hubs and gently easing each piston in and out and applying a tiny amount of rubber lube to the seals, cleaning off all residue. There’s no sticky pistons, no deformed discs and no contaminated pads. There’s no air in the calipers and all flexible pipes look like new.

I’m soon to start my annual maintenance process and wondered if anyone might have other suggestions I could add to my jobs list?

Thanks

Gary

Oh, can someone direct me to the correct brake pads for the Caparo calipers please? I went through this route this time last year, apparently the mintex compounds aren’t approved for road use! So I swapped the pads side to side with no difference to the mot results!

My experience is that the pads matter. Pads which need temperature won't heat up as much on a light car. It also matters how much of a braker you are. Mintex pads came with the ventilated disc kit for my Roadster, and gave me exactly this problem. On the rollers, balance was all over the place. On the road, it was evident for the first few seconds of application, then enough heat came in for them to work, but for my light use of brakes it didn't work. I went to Greenstuff, which were fitted whan I bought my Roadster on standard pads and no further issues. I realise that some hate Greenstuff. I also know that most find Mintex fine. For me Mintex did not work.

I think that we all evolve favourites over time and with experience. And we all follow different routes, because we can't individually test everything, but we all know what works for us.

As I said before, brake pads interact with your individual style. I know I'm not a braker, so the track based pads never get hot enough for me. OIl and grease really won't make much difference. Stay with the right viscosity oil, but any grease will lubricate kingpins, and it would take a lengthy scientific test to establish wear patterns of greases over time.

Dampers are over discussed. Take them off and see how it feels. Having had two fails, I know that on the road, you just can't tell much difference. I know that Spax single dampers are as good as AVO adjustables, within a few % and that Spax adjustables are slightly better. For me anyway.

I also know that if you have a six leaf spring rear, replacing with four leaf springs and a Panhard rod will make a significant improvement to ride and handling.

^^^^^ All relevant to Trads.

There used to be an old school MOT tester who used a Tapley meter (decelerometer) to test brakes. If it fell off the seat car got a pass

My money would be on a tyre to brake roller friction variance.

Tyre to brake roller friction variance is a critical factor in the accuracy of roller brake testers (RBTs), with measurements heavily influenced by tire pressure, vehicle weight, rubber condition, and roller surface roughness. Significant variance is introduced because RBTs measure total braking force which includes the resistance between the tire and the roller rather than just the internal brake components.

A Morgan is a very light car, so damn light in fact it's likely outside of the brake roller manufacturer's lower mass tollerance established when they designed the equipment, cars are much heavier these days so that's the standard they will have designed for. Find a friend with an equally well maintained car around the same curb weight as your Morgan, and put it on the same rollers, I bet it'll also show a similar inballance.

Anyway, you can always insist on a Tapley meter, Monty has an LSD so that's what I mandate. If you're testing the Sport Green 2012 Plus 4 in your profile you're a man of great taste as you have the same car as me, it would also mean you'll have an LSD so you really shouldnt be dropping the rear in the rollers as you'll cook your plates. In a clutch-type LSD, the wheel speed diferential creates intense friction and heat in the clutch plates as the LSD is doing its job by trying to lock the wheels together while the machine is forcing them apart.

You clearly have good mechanical knowlege and are maintaining your Morgan with great care, so please excercise your right to the Tapley meter as I'm confident you aleady know it makes sense

Reassuring to hear, and puts it in context.....as you know a trad Morgan are very prone to the back end locking up and potential to go sideways, the weight also transferring forwards and passing thru to the front wheel braking and without brake reaction bars the front brakes lean forward because of the chassis flexing. All endearing features that can create a few heart stopping moments in an emergency stop.So I was a little surprised to read just the latest posting


Must admit I didn't read all the earlier postings, mea culpa!

Grumpy, I take mine to PSS at the Caerwys junction on the A55. They use a decelerometer for brake testing and yes you are absolutely right about the modern roller brake test. The Mog is way to light to afford adequate friction under braking and the multi variable readings you get will predict nothing. Made worse by the fact that drums over brake momentarily before becoming consistent in brake force. This causes the tyres to jump or skip on the rollers.

For those who are interested or may only have experienced modern MOT testing - this is a Tapley meter

I'm quite proud of mine as it still has the storage box


This is how they are set level, usually in the passenger footwell - the base is heavy cast iron


This is how they read - deceleration in %age of G, the higher the number the harder you hit the windscreen