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MG MGA - Brake system advice needed

I've been having some ongoing issues with my brake system on my '59 1500. This winter I want to thouroughly go over the system. I'm planning to change to silicone brake fluid at this time. I plan to switch to the braided stainless steel teflon lined brake hoses also. Is there any other places in the system that will need to be replaced when switching to silicone? Is there any issues with the master cylinder that would need addressed during the change?

Thanks folks for any advice.
Jerry Murphy

Replace every piece of rubber in the system including the the rubber parts in the master, wheel, and slave cylinder as well as the brake light switch.
John H

If the brake light switch is an original, keep it. The replacements are useless, the old Lucas ones just keep going.

Otherwise the standard rubber brake hoses are just fine, the teflon ones are just more expensive and offer no major advantage unless you drive in extreme conditioins.

Seals should be replaced in the MC, and wheel cylinders. The cylinders should be lightly honed or cleaned tomake sure there is no rust. If there is any rust they should be replaced (how much is your life worth compared to a couple of hundred $ on new cylinders?)

Don't forget the flexible hose at the axle. The brake lines should be flushed to get rid of all cr*p in the system (compressed air will do this but have a helper with a BIG rag at the other end of each line to prevent spraying old brake fluid over things

If the cylinders are old, consider changing the bleed nipples out too.

The clutch slave seals should be changed too, but because the cylinder is so cheap (and so prone to leaking of worn) I'd coundel just throwing a new cylinder and hose in here if the old one is suspect. If you leave out the braided teflon hoses, you will probably come out cheaper.
dominic clancy

I am happy with the switch I did three years ago. I agree with Dominic. Replace all the rubber bits, hone/replace questionable parts, and save your money on the braided teflon hoses unless you like the look or you just want them. I used a compressed air tank designed for flushing air conditioners with an alcohol solution. Worked well.
Tommy

Hi Jerry. How are your metal brake pipes? If there is any obvious rusting or corrosion, you might want to strip out all the metal brake lines and replace them with copper nickel ones. Copper nickel brake pipes are stronger than steel ones, and do not rust. I believe that ordinary steel pipes can look perfectly good on the exterior, while being severely rusted inside, due to water absorption by regular brake fluids. I agree with the other comments previously offered. As for the brake light switch, I have found that American made hydraulic brake switches are available, and seem to hold up pretty well, even when using silicone brake fluid. Any decent auto parts place should have an American made generic brake switch with the proper threads to install in your MGA. Cheers, Glenn
Glenn

Jerry,
If your brake piping is origional, I would consider replacing all of them. The replacement brake piping kit is about $100 and very easy to work with. You never know the internal condition of the piping and with a single system master cylinder there is no room for error. Have a good day!

John
John Progess

Thanks very much guys. I'll take the advise given here and hopefully be in great shape in the spring.

Jerry
Jerry Murphy

These guys list stainless steel brake line kits (also fuel lines) for the MGA:

http://www.classictube.com/
Del Rawlins

I was wondering about Classic Tube as well. I believe they have SS and "OEM" brake lines, pre-formed, for the MGA. Does anyone have any experience with these?

George
G Goeppner

I am with Domonic, keep the old switch if it is original. No matter how old it is, it will outlast the replacement switches. The switches fail as a result of contact arcing rather than brake fluid contamination and the new switches have such light duty contacts, that they fail in a very short period of time (I had one fail after only two weeks). If you want to insure a long life for your switch, make up and install a relay/arc suppression circuit in brake light circuit. Instructions for making and installing such a circuit can be found at: http://www.omgtr.ca/technical/brakelightrelay/brakelightrelay.htm
Cheers - Dave
David DuBois

George,

I installeed the cupro-nickel pipes from SF during my rebuild. I was totally happy and found that the forming was not difficult at all. I bought a tubing forming tool but found it much simpler to form gently by hand. There was no kinking at all.

I really don't know what to recommend for the brake light switch. My original lasted ~47 years with over 25 of them off the road and dry. My replacement is only about 3 years old right now. Keep watching this BBS. If I get 47 years out of it, I will post a follow-up:>)

By the way, my replacement switch is an Intermotor brand P/N 51620 (Moss 141-700) made in ,or repackaged in, Nottingham England. Is this the same part that everyone else is dissing?


Chuck
Chuck Schaefer

Jerry, regarding the hydraulic brake light switches, my original Lucas switch expired after 44 years. Hearing of the bad reputation of the new switches, I ended up using a switch from a Volvo 122. It threads right in and works great. It is a little smaller than the original switches, but it is not noticable. The Volvo part # is 1501091. Should last for years.
Emmanuel Kafant

Chuck - I purchased a couple of Moss brake light switches several years ago that didn't last 6 months, but I don't know if they were from Intermotor. The only thing I know about Intermotor components for sure is that the points that they make for fuel pumps are less than stellar. I also purchased brake light switches from NAPA (again, no idea who makes them) and they too were short lived. that was when I made up the relay/arc suppressor circuit and installed it in both our TD and MGB and I haven't had a bit of trouble since then - that was about 5 years ago. I got so paranoid about the switches failing in both cars, that I also installed a tattle tail light inthe corner of the dash that come on with the brake lights, so I know when the switch is working. Cheers - Dave
David DuBois

Dave,
Perhaps the switch I have is a "good one", whatever that means. Hopefully so. I am running high-power halogen brakelights and a custom designed 3rd brakelight powered off the same brakelight lines. So the load is shall we say, above average. I have no explaination as to why mine has survived a few years and you get only a few months. Perhaps it is my limited driving.


A cap across the brakelight switch will help save the contacts a bit. And an anti-parallel diode won't hurt either. But perhaps the contacts are designed for a negative ground vehicle. Some switches are designed for unipolar current flow with differing materials used for the 2 contacts.

I like the idea of a telltale light for the brakelights.

Chuck
Chuck Schaefer

This thread was discussed between 13/11/2006 and 17/11/2006

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