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MG MGA - Brake piston return, master cylinder
Got a new master cylinder (Moss 180-670), and the box it came in shows "TRW" from Taiwan. I'm using silicon fluid.
I bench-bled it and had no problem with the clutch side.
The piston on the brake side, however, takes about 20 seconds to return.
When all fluid is expelled from the brake side, it takes less than a second for the piston to return.
I pushed the piston in and released well over 200 times with no fluid on the brake side and then replenished the fluid and tried again; still slow as before.
The sum total of my knowledge of master cylinders before this was how to check and replenish the fluid level, so I'm not sure what the next logical step would be.
Any thoughts? Thanks, as always.
|Send it back. This is not the first problem with the Chinese made TRW master cylinder. No one should be buying those things. Last I knew, they had never fixed the continuing problem of too much residual pressure causing the brakes to drag, and that has been going on for at least a few years now. I have a web page dealing with the problem in 2010.|
|Buy the original OEM master cylinder produced by AP Caparo. No problems.|
|I agree totally with Barney and Neil.|
The AP Caparo MC is a class above all the rest and worth spending that little bit more to purchase. Where braking is concerned why compromise with safety, both for yourself and the car.
|So glad to hear all your comments; last thing I needed was to fix, repair, or alter a new item to get it to work. |
The AP Caparo web sites seem to be more into tooting their horn than directing me to where I can purchase one of their MGA units..
Is there a stateside distributor for these units? Or do I need to contact AP Caparo directly and work it out with them?
Again, thanks for your help.
I cannot answer your State-side question. but I can tell you that Bob West does them over here and regularly posts to the States.
|Rick, I just got one from Bob West. Very quick service|
|Well, looks like a no-brainer here; I emailed Moss and described the problem in detail. Not much of a response relative to a resolution, but there's now no doubt that they're aware that their TRW master cylinders have been and are building up a bad reputation. I suggested they look into a possible relationship with AP Caparo. |
Anyway, I'm returning it.
I just finished emailing Bob West, as it appears there's no distributor for the good m/c here in the states that I'm aware of.
Steve; during my web search, I ran across a lengthy thread about your hellish experience trying to get one of the crappy master cylinders to work right. So glad to be spared that.
Thanks, all of you, for your collective input.
|I used to be a great advocate for silicone brake fluid but no longer use it. Some years ago I put it in my nephew's TC with a resleeved master cylinder and the pedal would not return. Eventually we cured the problem. Silicone brake fluid is not as "slippery" as the conventional type. Last I heard silicone brake fluid was only available to special order, it may no longer be available in South Australia.|
|No problem over here Barry. Awash with it. I have always had silicon in my MGA (since 1996). My issues have always been with the quality of the MC engineering. At the time it would have been easy for me (like you) to have blamed the fluid. Instead, deeper investigation eventually provided evidence of poor manufacturing tolerances in the MC. The new AP Caparo MC I installed worked brilliantly from the outset with exactly the same fluid, thus eliminating the fluid as a source of any of the troubles. Can you be certain of the engineering qualities of your resleeved MC? What is their quality control system? etc|
|Given the marginal extra cost of a new cylinder and shipping compared to two lots of shipping and a resleeve charge, I am amazed that resleeving is an issue except for cylinders that are NLA!|
I would be greatful for some advice of what to do.
Back in 2006 when passing Bristol on holiday I visited Moss Bristol Branch and bought a mastercylinder for my ongoing restoration of a 1600 Mk1 from 1960.
When reading this thread I am starting to get worried of what will happen when installing this MC and testing it for the first time. It is not opened an is still in its plastic bag!
Is it problem with all TRW MC:s or just some of them.
The text on my carton says PMA703, Girling P0106394 and 408-05/12/21 (I suppose that's the numbers from TRW)
The information from Moss says Bin B02-11-03, GMC109, B/M/CYL TNDM AS&M> 63.
Shall I contact Moss and send it back for test or rebuild or forget it and buy a new one from AP Caparo?
Is there anyone who's got help from Moss concerning this issue?
Anders / Sweden
Two days ago, before I returned the faulty master cylinder, I could have compared the carton text with the one I returned. Unfortunately the m/c and it's box are on their way back to Moss now.
I did email them about the problem I was having with it, in detail, and they made no response regarding it's failure; only that there'd be no problem returning it.
I know it's not much, but that's about all I can offer.
I just received credit notification from Moss on the cylinder I sent back. In it, there's a number they used that I recognized from the box the cylinder came in: 5-37344334
Show some photos from the carton I have.
Have tried to get in contakt with AP Caparo but haven't but with no luck!
|One more photo|
|Unfortunately that's the crappy TRW one! |
References to Girling and Lucas are irrelevant as the original was supplied by Lockheed.
Much of the new "Lucas" branded stuff is poor quality.
|From what I can recall, your carton isn't exactly like mine was, but my memory is sketchy; I can't be certain...|
I (also) went to the AP Caparo web site and found that it offered nothing to assist those individuals looking to buy one of their master cylinders; everything seemed to be keyed to promoting the company and little else.
Bob West in the UK, however, carries the AP Caparo cylinder for our MGAs.
His website is http://www.bobwestclassiccars.co.uk.
You won't find anything on his website that makes reference to the cylinder, but if you contact him at SRX210@aol.com, and inquire about cost and availability of the cylinder for your MGA, he will let you know how to obtain one from him.
I ordered one from him several days ago. He takes credit cards.
You are correct about Bob's website. He is not that savvy with IT. He has a website because everyone says he should have one, but he does not do much updating on it. He is not great on emails, but improving a bit. He does most of his work on the old fashioned telephone and most of his business is on word of mouth recommendations. I only stumbled on his stock of Caparo AP MCs by chance when discussing my MC problems. He informed me that he has countless MGA owners coming to him with MC problems and the first thing he does is sling out their MC and fit a Caparo. All his rebuilds are now supplied with Caparos.
This thread was discussed between 07/01/2013 and 14/01/2013
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