MG MGB and MGB GT Tech Talk
I need to replace my brake master cylinder and I see you basicly have two choices, the OEM one or the Chinese knock off. There are also a few on the internet that are made by Lucas. I guess these are also the OEM ones Moss sells. Is one better quality then the other? Last one I purchased about 5 yrs ago is leaking fluid through the front where the push rod is. I think it was the cheaper one that I bought.
thanks,
Cheaper is rarely better. Rebuild the original one. I use Whitepost Restorations in Virginia. ...and, what year?
72 roadster.
I already knicked up the push rod shaft on this one trying to get it apart. What a pain in the ass that white nylon bushing is. I think I'll just have to buy another.
Check with Basil Adams on this forum. He has the good stuff (TRW, Lockheed) at a good price.
The knock off cylinders that I have seen are made by URO which is not a Chinese company. I believe they are EU. So far, there have been no complaints.
PM sent. Just so everyone knows, the dual line, non-servo brake master cylinders for '69-74.5 MGBs I have available new are the Asian unit Moss sells for $159.95 I can get you for $115 plus shipping. The new (made in UK) TRW/Lucas unit is $124.00. I prefer the TRW but it's your choice. The TRW box does say that the warranty is voided if you use silicone brake fluid - I've never used the stuff and don't know why some people do but I thought I'd disclose the factory disclaimer before anyone's disappointed :) Basil
Why use silicon? I do because I would like to keep the paint in the engine bay on the sheet metal. If there is a less caustic brake fluid on the market, I'd use it. As far as I can tell the only bene DOT 4 has over DOT5 is boiling point. Don't race and don't see the big deal. What am I missing?
BTW, Basil, what is the best choice of MCs for silicon?
Silicone doesn't lubricate the internals of the braking system. DOT4 does and also swells the seals, making for a tighter system. RAY
Basil.
Check with your sources before getting too carried away. The TRW/Lucas master cylinders are made in Taiwan under the auspices of Lucas Japan.
The silicon fluid warning lable is put on the box by the US importer, not by TRW. TRW makes no such requirement.
The only master cylinders currently being made for the MGB in the UK are supplied by Caparo/Lockheed. These got really expensive when the pound went high.
kelvin
I'm also interested to hear why DOT5 is a no-no on a newly rebuilt system. I've used it for years on newly rebuilt hydraulics with no issues yet, and like it because if you spill it, you don't need to worry about repainting your car.
As far as I know, silicon is an excellent lubricant for rubber. It does not swell rubber, like hydrocarbon based lubricants will. In addition DOT4, which is glycol based, will absorb water, and that water can do a lot of damage to a brake system....DOT5 will not absorb water.
Bruce. Rather than realigning this thread. I'd suggest doing a search on Silicon Brake Fluid for more information.
The most important thing to remember, is that if you have had success with it. There is no reason to not continue using it.
kelvin
Although most people find it strange, the water absorbing properties of conventional brake fluid are an intentional property. The paint removing feature was a side effect! :)
LOL:
Many of the problems with silicone fluid are because it doesn't absorb moisture. But it doesn't eat your paint.
