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MG TD TF 1500 - How do you properly rebuild Brakes?

As an estension of my Sleeving brake cyls post, how does one correctly hone and rebuild the brake components of your T-series? Are limited budgets not reason enough to do sleeve the cyls or MC?

I'm faced with this situation of low funds but I do not want to look back at my "awakening" and say "Gee I guess I should have sleeved the brakes" becuase there might have been a devastating reason for looking back and saying this. One reason I am not prepared to say.

I had already purchased the rebuild kits for these so in wanting to do it all myself, thought i would give it a go. If experience of the board prevails, I'll bite the bullet and toss the kits, spend on new or sleeved and call it a day.

Meanwhile, I have the cyls here at work waiting to get re-built. Here is a list of question I hope can be answered one by one and hopefully this list can be used as a future reference to all. Feel free to add questions to the list if I've not thought of it.

Is it as easy as just honing the bore to remove pits and ridges?

How anal do I have to be? What is the largest ID alowable before it is trash?

Does it need to be polished like chrome or is leaving the fine hone marks acceptable?

What about the piston? Does it need to be treated in any way?


Cheers
Vince
vping

If you have pits, you will not hone them out. They will be too deep. If there is one area not to scrimp on it's brakes. Spend a little now, do it right with full sleeving, full kits, dot 5, and don't worry about it again for a VERY long time.

As for ID, I don't know as mine were sleeved. Not polished but not very rough either. The stones for honing basically break the glaze and clean very minor surface imperfections. As for pistons etc. I just wire brushed mine down. Make sure to liberally use brake fluid to lub things when you assemble. And have patinece bleeding.

If you sleeve you will need your kits to don't toss them.

The one hint I would give is to check your adjusters well before you take apart. I wish i would have, I would have put a shim in them when re-assembling so I had a little more adjustment left. I'm about maxed out so some day I'll have to pull the front drums (not fun) to shim those adjusters. Even with the new shooes I put in.
l rutt

I honed the brake cylinders on both of my cars with excellent results. One car had sat for over 20 years and the other for over 10...both are now running Dot 5, not leaking and have excellent braking capabilities.

There were no DEEP pits but there were a few small ones...these were deep in the cylinders and not near the outside edges where they could/would leak.

After honing, your cylinders will not be shiny on the inside but will appear smooth with very faint hone marks.

I definitely recommend that you at least try honing before spending the money to have them sleeved.

Also...you don't need to send them to White Post...any of your local machine shops can sleeve them and do just as good a job as WP...and probably cheaper (I notice WP doesn't advertise a price any more). Get a quote and see.



Gene Gillam

I honed my wheel cylinders around 10 years ago and the results were good. My bores had a fine honing pattern and this didn't seem to be a problem. As I remember, the pistons are isolated by the rubber seals, so a good cleaning is all that is necessary. Sometimes you will find that, as long as the fluid hasn't been sitting for years, collecting moisture, the bores might be pretty clean and it is just the rubber seals that have rotted due to age. If they are excessively pitted and honing does not smooth them enough, Moss is showing new ones (repros) for $40. You can always sell your repair kits on ebay to help pay for them! If you look around, you can find resellers such as LBC co. that will offer up to a 15 or 20% discount.
Steven Tobias

Mine were seized and had to sit in 'dolphin killing' liquid for about a week... the mechanic then got them apart...he honed them and rebuilt them...think all 6 and the master cyl cost me about $160.00 ... that was back when new ones were $90.00 each or so.... haven't had a problem with the brakes in 25,000 miles and have silicone fluid...
gblawson(gordon)

I wasn't sure what to do either, and my brakes were non-existent... heck, two wheels were completely frozen. But after adding up all the other unavoidable costs (new lines, new hoses, new pads, and having the drums trued up on a lathe, etc) I didn't have the money left over for resleeving, so I settled on cleaning, light honing, and rebuilding.

So far they look good and no leaking, but I'll admit they haven't had much road testing yet.

I'm thinking I went from zero brakes to at least 95% brakes and it cost several hundred dollars without sleeving; when I start to get brake leaking, I'll start resleeving on a cylinder by cylinder basis. In the meantime, I'm very confident of the braking ability.

Life is often about doing what you can with the cash you've got, otherwise we'd all drive M-1 tanks on the road for safety, right?



Geoff Baker

Really check for pitting in the area where the seal travels and rides-that is the most important. If there are deep pits there that won't polish out, time to sleeve. Linear scratches are also bad. Same thing with the master. I always put an automotive-type o-ring under the head of the front cylinder piston. This will keep it sealed when at rest. I totally agree with I Rutt- brakes are no place to scrimp. Especially considering that unlike modern cars, this is a single system- the fluid leaks out and you have total failure. Also, the price of linings and shoes being what it is, you don't want to soak new or serviceable linings. Gene, you must have better machine shops in Miss.- the couple shops here have no clue! George
George Butz

"Gene, you must have better machine shops in Miss.- the couple shops here have no clue!"

George, you don't know the half of it. I've got two friends here, one a retired shipyard machinist and one a retired Alcoa plant manager...both with excellent backyard machine shops and great prices (next to nothing or free).

But I do have to admit even our auto machine shops are good...at least the ones with workers over the age of 50.
Gene Gillam

As a rule of thumb, I advocate rebuilt or new rear cylinders as they seem to take more abuse with the mechanical arms for the parking brake set up. The fronts will usually hone out nicely. I've never had luck with honing out the MC until last time around. I must have finally got lucky. But then, in the past I ran with DOT 3 and now I'm trouble free with DOT 5.

warmly,
dave
Dave Braun

Is the Castrol LMA I use in my B the dot 5?

What about brake lines?

I've been asking all these questions assuming that my system needs work but I'm not really sure. When I got the car, the wheels were tight and when I took off one cyl the piston was stuck but it came out quite easily and the bore looked OK 'cept for some residue. I found evidence that the cyls were rebuilt most likely prior to storage because the used piston seals and other components were in a bag in the tool box. The u-joint was also rebuilt. I have decent pressure on the pedal too.

I'll first look at honing and see what they look like on the inside before I resort to new or sleeves.
vping

Dot 5 is silicone brake fluid. The only way to go I think. Definitely change the rubber hoses. I you flush the steel lines they may be ok. George
George Butz

I agree with George...DOT 5 (silicone) is the way to go. The problem with it though is you'll have to throw away all of your rubber parts that have been in contact with the DOT 3 and replace them with new rubber. You'll probably be doing that anyway so no big deal.
Gene Gillam

This thread was discussed between 23/03/2010 and 25/03/2010

MG TD TF 1500 index

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