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MG MGA - Caliper Slow Release

I thought I would start this thread afresh instead of continuing my MC slow release.

As part of my disc brake conversion in 2003 I bought a new pair of Lockheed MGB calipers. Since then I have always had 'minor' issues with my braking, including suspected slow release which usually had me looking at the MC. Following Barney's comments in my other thread I have finally got round to taking the calipers apart. Bearing in mind these were a 'new' purchase from a very well known supplier I have been astounded at what I found.

I have only taken one caliper apart so far but, as you will see from the photos, the top seal was distorted, as was its metal retaining ring. This appears to have caused the piston to move off centre and there is smooth wear at the bottom of the cylinder and on the piston skirt.

And so to the question. Do I simply refurbish with new seals or do I bin the lot and buy new units? All comments and suggestions most welcome.

Steve

Steve Gyles

I would think that at 30 each new it isn't worth messing around with a refurbishment....
dominic clancy

Are they that cheap?
MGA calipers $119
Art Pearse

I paid 52.50 each plus 17.5% tax in 2003. They are down to about 40 new now. A seal kit is about 12 per caliper so it makes you wonder.

Steve
Steve Gyles

Would you take the new ones apart to check them out before using or could you see any of that assembled?
gary starr

Excellent question Gary. The poor assembly was not obvious until I split the caliper and pulled the pistons. Where do we stop or even start with these recent OEM bits of kit ?

We have had major issues with the Lockheed MC in recent years until AP Caparo got hold of the machine tools and improved quality. Are we now also witnessing the same thing with others items? My caliper has been undisturbed by me until today. It beggars the question of the company training/quality control etc.

Are there non Lockheed MGB calipers out there that might be to a better standard because it's a sorry state that something as vital as the brakes should have such poor engineering standards from that company.

Steve
Steve Gyles

Steve has B callipers which are available at
http://www.mgpartsuk.co.uk/store/index.php?route=product/product&path=330_349_360&product_id=5950
for 29.50.

As I wrote, I don't think it's worth messing around at that price ! But Steve doesn't have anything else to do unless Mrs Gyles is reading along!
dominic clancy

She is! ......and I bought the seal kits yesterday before dismantling!

But I am inclined to your thinking and what we preach about not messing around with shot braking components. Thanks for the link. Does he come Dominic recommended?

Steve

PS. Yes, I know them. Got my steering wheel there 15 years ago. Just off the M40/42.
Steve Gyles

Steve, if you reassemble yourself, at least you know the QC involved!
Looking at your piston, the scuff is way out of where the seal would ride, so Ok to re-use.
The other bit of the seal is in the groove.
Art Pearse

I would re build seeing you already have the seals and see if it fixes your slow release issue
Mike
Mike Ellsmore

I am also replacing the flexible hoses while I have it all apart. I have yet to decide whether to go for new calipers but seeing I have the seal kit I will fit them and see what I think.

Steve
Steve Gyles

My mind is made up. New calipers. Closer inspection under a magnifying glass of the piston on the offending side of the caliper showed slight score/wear marks. I am not going to mess around any more. They have to go. I also looked at the pads. The wear backs up my suspicion that the piston was not releasing fully. The groove in the pad on the offending side was full with brake dust debris (photo). It was also more worn.

The score marks on the removal tab also indicate how much trouble I had trying to remove it, it was so tight even after trying to force the piston back.

Steve

Steve Gyles

It is often the way with brake and clutch components that it's only on VERY close inspection that the real state of affairs is revealed. in my experience a refurb is never as good as a new item, and with all the dirt and hassle of pulling everything apart I would rather do the job just once. I really should get a new pair of front calipers for my car, the ones fitted are now 26 years old and even if they seem to work well and don't leak at all, they must be coming to the end of their service life. All the other hydraulics have been replaced over the last few years, but the calipers were out of stock when I ordered them.

Mrs Stevie Gyles

Ordered new calipers and flexible hoses. Interesting that the guy I spoke to said that my 'original' Lockheed MGB calipers would have been refurbished units in 2003 and not 'new'. Is this correct? When did Lockheed stop making them?

Steve

Ok, Mrs Stevie Gyles, declare your credentials! Don't hide under a mask. Your points are valid.
Steve Gyles

I am amazed that Mrs Stevie knows so much about cylinders and is apparently willing to get down and dirty: definitely a keeper!

dominic clancy

Dominic

Not sure about getting down and dirty at the moment. We have just had to cancel all our planned MGA driving for the next 4 months or so. She goes into hospital at the beginning of June for a hip replacement. I hope the parts they use are to a better quality and fit than some of our MGA replacement parts! I think I may offer to turn the ball and socket joint for her on my lathe.

Steve
Steve Gyles

then best wishes for a reliable surgeon, the right parts delivery and a super quick recovery fo Mrs Gyles!
dominic clancy

Thanks Dominic. All in hand. He comes well recommended and is our local equivalent of the MGAGURU!

Steve
Steve Gyles

You will have to see if you can get some Bob West sourced hip joints Steve, he always seems to come up with the best quality parts.

Not sure how well Mrs G will take to the obligatory external grease nipples though! :-)

Hope all goes really well though.
All the best
Colyn
c firth

Just to finish off this thread. I have just finished replacing both calipers and all 3 flexible brake hoses. Car runs and rolls so much freer. It's amazing how one poorly fitted and damaged seal could cause so many issues over the recent years. I bet my MPG will improve significantly. It's just a shame the car is now going to get so little use over the next 3 months.

Steve
Steve Gyles

Not quite the end. I have just dismantled the other caliper. The top seal retainer in one piston was similarly damaged as the one shown in my opening post. Also, both pistons were incorrectly located. There is a cut-out section around the top edge of each piston that should be orientated in a particular direction. Both pistons were 90 degrees out. It beggars belief that two calipers sold to me 'as new' were both badly and incorrectly assembled.

Anyone want a pair of Genuine Lockheed MGB calipers for rebuild? Yours for the postage.

Steve
Steve Gyles

Photo of the retaining seal and piston in the second caliper. The score marks on the piston are where the second (inner) seal fits. Presumably the damage to the retaining ring and subsequent distortion of its seal pushed the piston off centre and caused it to rub against the cylinder wall adjacent to the the inner seal.

All in all a poor bit of workmanship by a company/person supplying restored items to the trade.

Steve

Steve Gyles

Steve

With MGB bits like your calipers have you also tried the MGB Technical list. I have done so successfully for a couple of engine related queries. There is currently one thread there on 'sticking servo' that is at 57 entries.

Paul
Paul Dean

Paul

I did ask them about the pad retaining springs orientation and got the correct answer. I often look at 1800 engine threads purely out of interest.

Just done a longer ride in the car. Born again on performance. It's lightened up the front end feel so much and of course acceleration & overall performance has gone up a notch. I just rue the last dozen years of the residual brake friction, of which I was totally oblivious. It's only when it is all freed up you realise you had an issue. Another bonus is that the intermittent brake squeal has totally disappeared. I wonder if there are other 'squealers' out there who have the same issue that I have just uncovered? I can only assume that whoever built my calipers so badly has done the same to many other sets!

Steve
Steve Gyles

This thread was discussed between 03/05/2015 and 25/05/2015

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