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MG MGB Technical - Removing Pedal Cover

Do I need to remove (or loosen) the brake light switch to remove the pedal cover?

I've removed the four screws at the base of the cover and it still seems reluctant to move.

Jeremy
1974.5 MGB
J. Palgon

Jeremy - No need to remove the brake light switch, just disconnect the wires. As for the cover being reluctant to move, a judicious use of BF&BI (Brute Force and Bloody Ignorance), the gasket around the bottom of the cover kind of glues itself to the cover and the car, making it difficult to break loose. Good luck - Dave
David DuBois

Dave,
Thank you, yet again, for helping. I did eventually remove it by rocking it back and forth, and pulling on it. It seems my gasket at the bottom has become a sort of gunk. There's not much in the way of intact gasket left.

Unfortunately, removing the cover hasn't cleared up my clutch issue all that much. I've been losing clutch fluid very quickly--the resevoir is going dry about once a week. When it has fluid the clutch is fine. Obviously, when it doesn't the clutch doesn't work. I'm trying to find where the leak is.

I've checked the clutch lines and they all look good and aren't dripping. The clutch slave seems to be dripping ever so slightly from the boot. So that might be the problem. But there's lots of liquid residue beneath the clutch master cylinder (and all around that section of the engine compartament). Also, I find my feet wet from time to time. So it seems there a leak somewhere up there. I just couldn't locate it easily. It's apparently not as obvious as I'd hoped.

Jeremy
J. Palgon

Jeremy,

If the slave is leaking slightly when you look at it, I'm wondering what happens when you step on the clutch pedal?

While the car is up on jack stands crawl under it and look at the slave while someone pushes in the clutch pedal. If my suspecions are correct your boot will expand as it fills with hydrolic fluid from the pressure. The boot then slowly lets it leak out.

If that is the case, you will need to replace or rebuild the slave cylinder.

From my experience, I've never had good results from rebuilding at home. There are several companies that rebuild and resleeve the cylinders or you can go for new.

Then Murphy's law usually comes into play. Once you rebuild the slave cylinder and it is nice and strong, the master cylinder usually goes quickly thereafter. I try to replace them together unless I know the master cylinder is fairly new.

Cris
Cris DeYoung

Jeremy,
I would be inclned to agree with Chris on these points.

Rebuilding the master / slave cylinders can be a do it at home job but for the small expense involved and the levels of frustration saved it really is worth considering paying a brake and clutch place to do it for you.

If you do go the overhaul route then replace with new if possible or failing that have them sleeved with stainless steel sleeves.

From a personal point of view I have always regarded the entire system as one unit and overhauled it accordingly.
The theory being as stated above is if one part is due for replacement then most likely others will be in the same condition.

Cheers , Pete.
Peter Thomas

I will make it unanimous regarding the slave cylinder, it is probably the main culprit and needs to be replaced. I would also suggest that the master cylinder be rebuilt at the same time as it sounds like it has also been leaking. The master is relatively straight forward to rebuild and can be done at home easily, although you will need some way to hone the cylinder. If you pull the master cylinder to rebuild or replace it, take it to a machine shop and have them helicoil the holes in the mounting flange for 5/16 SAE threads so that you don't have to fuss with trying to get nuts started in a location where you can't get your fingers, it will make reinstallation on the master cylinder vastly easier. Good luck - Dave
David DuBois

Leaking fluid at both master and slave ends does imply that both should be dealt with. And if you are doing both cylinders replace the flex hose as well. Empty the old master through the slave nipple (adding clean fluid if necessary) to flush the steel pipe.

I'd advise refilling the system from the slave nipple, that way you shouldn't need to bleed at all, which can be a right pain. I used a gunsons EeziBleed on very low pressure, but I've also read of connecting a brake caliper nipple to the clutch slave nipple and using the brake pedal to fill the lutch system, keeping an eye on brake reservoir level of course. Just fill until you can see fluid by looking in the master filler hole, then top up as normal. You should end up with about 1/2" to 5/8" of travel at the clutch slave push-rod.
Paul Hunt 2

Aluminum cylinder bores cannot be honed so I advise you just replace the slave with a new one. Since the master is cast iron that can be honed and rebuilt.

I am assuming of course that the slave on your car is aluminum as were all the ones I took off.
Mike MaGee

Guys,
Thanks for you input. As most fo you already know, I'm fairly new to working on cars. As such, I have a novice follow up question. I know that rebuilding invloves honing the cylinder. What exactly does that entail (some sanding, I imagine)?

By the way, I have a good friend who's a machinist at NASA and has a dozen antique trucks. He the one who helped me get my car running after 15 years. So, despite my extremely limited knowledge, I have some good help. Perhaps I can get him to alter the master cylinder as Dave suggests.

Jeremy
J. Palgon

Jeremy,

Honing involves using a flexable rod with honing stones on spring loaded arms it. There are many different sizes and stone grit types depending on your needs (the size of the cylinder that needs to be honed and the severity of the pitting, score marks etc.)

People usually attach the rod to their drill and go at it. I like to use some light oil to help with the process and keep the stones from clogging up with metal particles.

Cris
Cris DeYoung

Chris,
Do you know where I could get the honing stons and rod? Also, this seems like it would smooth out the barrel, which would be good for making a good seal and for maintaining fluid pressure. But I have good fluid pressure right now--it just seems that I have a leak. Are we to assume that the leak is likely cause by poor sealing?

Thanks,
Jeremy

By the way, I just posted some pics of my master and slave cylinders (along with their leaks) at photos.yahoo.com/jeremysmgb in the problems and solutions album.
J. Palgon

Jeremy - All good auto parts houses carry and assortment of hones. The problam may be getting one that is small enough. If that is the case, a length of 3/8 hardwood dowel with a slot cut in one end to take a piece of wet and dry sand paper cut about i inch wide placed in the slot and wound around the dowel will work, albeit a bit slower than a proper hone. Useing either a hone or the sand paper, I squirt a little CRC Brake Kleen in the cylinder to act as a lubricant. Your machinist friend will know all of the tricks. And yes, a pitted cylinder bore can cause the leak, as can a deteriorated seal (the usual cause). Good luck - Dave
David DuBois

Jeremy, I suspect your friend, the machinist with a dozen antiqie trucks, has any size hone you may need.

Clifton
Clifton Gordon

Clifton and the gang,
My friend does have just about any tool he needs---usually. The problem is, his family moved to Washington while he remained here in San Jose. As is usually the case with such hobbies, the trucks are a family affair. Thus, most of his usual tools are his father's; and, as such, are themselves migrating to Washington as well. Last weekend he went to fit a new rear end on his 1950s White (his old rear axle met a tragic end while on the road) and found that his father had taken the oxy-acetaline torch the week before. So, these days it's a bit more hit and miss--unless he can borrow NASA's tools.

His family's collection is actually quite interesting. It includes 2 GMC Deuce-and-a-Halfs(one of which as made to be used in World War II and has been used in numberous films), the White, a '28 Mack AC, '48 Mack EE, '50 GMC, a jeep, 3 Model Ts (2 of which are hot rods), '40s Buick, and some other's I can't recall at the moment. And that doesn't even include the crane, about ten tractors (mostly Caterpillars), the three Whizzer motorized bicycles, fork lift, small motorbikes, and their daily drivers.

If you're interested, in seeing a few pics of his collection you can see them at http://www.geocities.com/charlesstangeland/ .

I have a bunch more good pictures of his stuff. Perhaps I'll get around to posting them on my photo site later today.

Jeremy
J. Palgon

For those interested, I've posted pictures of some of the vehicles (and a few of the animals) around my friend Charlie's house. You can view them in the aptly named Charlie's house album at photos.yahoo.com/jeremysmgb .

Jeremy
J. Palgon

This thread was discussed between 22/11/2005 and 24/11/2005

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