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TR2/3/3A TR3 Brakes

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ron wilson

Jedi Hopeful
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Have a 59 TR3A. Brake pedal is not spongy but if I sit in the car and push the pedal in then wait a few seconds and push it in again (doing this several times) the pedal eventually goes practically to the floor. Fluid container is full. With this limited info can someone tell me if the brakes need to be bled or does the master cylinder need to be rebuilt.
 
Ron,
Sounds as though you are not totally familiar with your car, at least from a mechanical standpoint. This is not to be meant as a snide remark. Most 3 drivers have pretty much built their own cars. I would think that bleeding the brakes would be the easiest and most logical first task. Also the cheapest. But I would go it one step further. How about changing all the fluid with some fresh and cleaning out the reservoir at the same time. Can't hurt. Air in the line will surely cause erratic and poor braking.
Stick with the fluid recommended in your manuel.

Bill
 
Aloha Ron,

A replacement of fluid is a good start, particularly if it is three year old or older or you have no idea of its age. All of the DOT 3 and 4 fluids will absorb moisture over time which will reduce the boiling point and deteriorate brake performance. I am assuming that you have checked and there are no apparent leaks. Usually, if air is in the system, pumping the brakes increases pedal stiffness as the air is compressed. Bleeding removes this air to give you a firm pedal on the first stroke. If the pedal moves closer to the floor board on successive strokes, it may be that either the resevoir is low or the master cylinder is not holding the pressure. If the fluid level is good, the situation most likely calls for either a replacement or rebuild of the master cylinder.

Safety Fast,
Dave
 
You , I hope , dont like fixing wrecked TR3's so I would say a through freshing up of the brake system would be a GREAT idea. Never short yourself on safety, do it once and do it RIGHT, you will never be sorry.
MD(maddog)
 
Ron,

I agree with the others. Get a friend, a piece of clear rubber tubing to fit over the end of the bleeder nipple, and start pumping out the fluid. It seems that if you were drawing air in at one of the wheels you would also be losing fluid. If you notice more air bubbles on one wheel than the others, check for any brake fluid inside the drum (rear) or around your pistons (front). If there are no bubbles and the problem persists you probably have a master cylinder problem. I rebuilt the entire system on my 1959 TR3A when I was 16 and found it to be pretty simple. I can't remember if there is a way to bleed the master cylinder on the TR3... It has been almost 20 years since I worked on one. Your car has the Girling system as opposed to the earlier Lockheed system. I don't know about your mechanical experience, but with a good Workshop Manual, it's a pretty straight-forward rebuild and would not take too long to accomplish. Good luck and try bleeding each wheel first and let us know if the problem went away. I recently found my old factory manual for the TR3 and may be able to get you some copies of the brake system section if you need them. I'll try to get my scanner working in the meantime.


Brian /ubbthreads/images/graemlins/cheers.gif
 
Rebuilding the rear brake cylinders on my TR3 was one of my first car projects (followed by rebuilding the SUs.) Don't be scared, just take your time and you'll find that things like brake bleeding are actually a lot easier than you think.

Just remember to start bleeding from the passenger rear first, then driver's rear, passenger front, driver's front. Also remember to have bleeder valves pointed up (so air escapes)in the event you remove the cylinders.
 
[ QUOTE ]
...Just remember to start bleeding from the passenger rear first, then driver's rear...

[/ QUOTE ]

If the objective is to start with the brake that is farthest from the MC then I think that would be the drivers side rear on a LHD.

It is closer 'as the crow flies' but because the flex-hose & 3-way connector are over by the passenger side hub it is farther 'as the brake line runs'. Same is also true up front as the 5-way connector is on the passenger side.
 
Geo, y'know, you may be right...I never even thought about the line connectors!!! I'm going to have to look at the bottom of my 3 tomorrow and confirm this on my car. Boy don't I feel dumb!
 
Your symptoms are classic for a master cylinder that needs to be rebuilt or replaced.

Spongy would indicate air in the lines...you said NOT SPONGY.

Full resevoir says that you aren't losing any fluid, so nothings leaking.

That leaves the Master Cylinder as the problem.

There's an easy test for this.

Pump up the pedal and hold alot of force on it. It should stay up. Then, reduce the force slightly. If the pedal starts sinking, the master's shot.
 
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