MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - MOT time!

Hi Guys,

Just taken in my mgf fo its first MOT since I bought it, and the major damage will be 3 new tyres (both rear ones are split on the inside!) and 2 new rear brake discs. Not too bad as long as changing the discs is a simple as it looks in the manual.

One slight failure concern I have is that the n/s parking brake was marked up as not working at all, and of course the overal efficiency was also down. Any idea of a likely cause for this? Is there any point at which the cable is likely to have seized or broken?

Also, they had to stop the MOT test for a while as the engine started overheating and coolant was apparently bubbling over the cap (assuming the expansion tank cap!). This car has never overheated for me before when driving or left running. Could it just have been the short time that it was left between me getting it to the garage and them starting it up again for the test? It was a 10-15mile drive in the sun to get there!

Any ideas?

Cheers
Dan Wavell

Ok, should be fine on the brake discs and will bleed the coolant system asap in case there are any air locks causing hot spots. But has anyone got any idea about the handbrake not working on one side? What's most likely to have gone wrong and how could it be fixed?

cheers

Dan
Dan Wavell

"One slight failure concern I have is that the n/s parking brake was marked up as not working at all, and of course the overal efficiency was also down. Any idea of a likely cause for this? Is there any point at which the cable is likely to have seized or broken?"

lie on the ground and look at the offending rear caliper and get someone to pull the handbrake on and off. You'll be able to see the movement, or lack thereof of the handbrake mechanism. If you see very little movement then it'll be seized. To double check remove the cable from the caliper and you should be able to move it by hand.

It's a reasonable straightforward job to repair. Just remove the caliper and proceed to clean up the handbrake mech. I remove the seal and cleaned the dirt out of there and then apply plenty of WD40 and worked the mech backwards and forwards for a bit until it was freed up. It's spring loaded internally against the piston and should spring back when released.

Saves £100 on a new caliper
Bob Millar

Bob, which seal did you remove? I'm having to loosen the handbrake mechanism manually approximately every three weeks, hadn't spotted an easy way of getting inside.

Been trying to find an overhaul kit that includes a new external return spring - I took the fact I could remove the OE spring by fingers alone to mean that it had lost a bit of oomph, contributing to the problem. Brakes International's caliper service kit has all the new hydraulic components but none of the handbrake bits :o( Mind you, £56 +VAT for a 'new' caliper isn't too painful.

Dan, schedule your brake disc replacement for a time of day when the peals of a hammer repeatedly striking a firmly rusted disc won't annoy anyone. It could go on for quite some time ;o) Strongly recommend replacing the pads at the same time, otherwise it'll be a while before the old (not flat) pads wear onto the (flat) new discs, during this period your brakes will be horrible and probably not perform very well on an MOT re-test... If you tend to use the brakes quite hard then definitely go for a higher spec, the standard pads don't live long if worked hard.
Mike Hankin

Cheers guys, will look at the handbrake cable bits on sat, hopefully it will just be a case of WD40 and some patience! Even if that only does enough to pass the re-test on mon and eventually needs more work.

Will be doing the discs at the same time, so should be a reasonbly good time to be hammering! Only thing is I only replaced the pads about 2 weeks ago in preparation for the mot and decided that the discs looked good enough to me! Think I might have to leave them for now and do some heavy braking to try and wear them in to the new discs!

Ho hum, the joy's of car ownership!
Dan Wavell

"Bob, which seal did you remove? I'm having to loosen the handbrake mechanism manually approximately every three weeks, hadn't spotted an easy way of getting inside."


Errr…ok technical (NOT!) description. Where the handbrake cable attaches to the calliper, there’s a large spring. The cable and spring are turning a shaft which in turn moves the piston. This shaft has a large nut on it. If you remove the calliper and retire to the comfort of your warm garage, stick the calliper in a vice and remove this nut. You’ll then see the whole shaft and at the bottom of it there’s a black rubber seal, although it’ll probably be caked with dirt. I removed this seal and cleaned all the crap out from underneath it. Then applying plenty of WD40 and using a spanner on the shaft I spent time moving it backwards and forwards till it was totally freed up. I haven’t been able to find an internal schematic yet but I’m assuming the shaft turns a cam internally which moves the piston. I also assume it’s spring loaded internally as it returns back to the starting position when released. The seal was a pig to fit back in and to be honest I cheated slightly by cutting off the internal lip of the seal and then applying a small amount of silicon round the internal diameter of the seal and using that to hold it in place. It may actually be a better solution as it should stop dirt working it’s way in as the original seal is really just a dust seal.
Bob Millar

Thanks Bob, I'd been avoiding disconnecting the hydraulics but it sounds like it's worth a bit of fluid (even 5.1) to get the thing onto a workbench.

Dan, if your pads are that new then they should bed onto the new discs quite quickly. Good luck for the re-test.
Mike Hankin

"I'd been avoiding disconnecting the hydraulics"

it wasnt too bad. We stuffed a rag into the end of the hose and tied it up high to minimise the leakage and with and ez-bleed kit it was a doddle to bleed
Bob Millar

Hmm, well I tried... still the mechanism doesn't return properly, seems to be a terminal case on this side at least. So just ordered a Budweg reconditioned caliper, £113.28 inc P&P but £35.25 refunded on collection of old unit, so £78 all in with a 2 year guarantee.

Hope you have better luck Dan!
Mike Hankin

This thread was discussed between 16/08/2005 and 18/08/2005

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now