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HELP!!! No Breaks

LLAngus

Jedi Knight
Offline
Last week I drove the B GT down to the next to the next town. The breaks suddenly went like a tomatoe. I got home by sumping the breaks. They would slow down and the pedal would sink to the floor. I crawled under the car and saw no break fluid on the ground or around any of the cylinders or disc calipers. I had a master rebuild kit and installed it. The breaks felt like they came up and the pedal felt great until I bled the breaks. At that time they started the mussy feeling again. I could see no fluid anywhere. Could the pressure failure switch allow fluid to bypass back into the master? The fluid did bleed out to the far rear cylinder but not like it should. I do not think I got the kit in wrong. /ubbthreads/images/graemlins/eek.gif
 
From what I understand, MGB brake MC's are difficult to rebuild at best. It's possible the MC is leaking internally.
 
I am going to buy another MC kit and try that. Has anyone had a problem with the pressure switch going out and how do you bypass? I don't want to buy a new one ($500+) if I can help it.
 
You might need to shop around. Think you will find one for half that. I too have heard that the repair kit is hard to do. When I bought my MGB the PO had put in a repair kit, but it did not last very long at all. Opted to go the approx. $200, price at that time, instead of trying to rebuild it again. Thought the peace of mind was worth then and KNOW it was worth it now.

Good luck and keep us posted.

Cheers
 
I think now the trouble is the MC. The light came on for the pressure switch after trying to pump the brakes to find out where the fluid is going. The fluid in the reservor is going around--out the front and in through the back. I could see bubbles coming out of the rear half of the reservor and see the fluid going over the divider into the front. No fluid leaked out of the resevor so it must be going in a big circle. Maybe I put something in wrong. I know I can get a new MC for $260 the $500+ price was for the pressure switch. I, also, took off a line into the pressure switch and the volume of fluid was small and quit before the pedal was completely down.
 
If you can push the car forward when its in neutral, your pressure switch works! If its in neutral & no wheels are locked & it won't move forward, the pressure switch is bad...but, a bad pressure switch is a rare thing...I've got good used ones for lots less than new ones...

...your problem is probably the MC - & rebuilding them takes a little patience because there're things you have to do that aren't in any manual...
 
I have a brand new Midget MC. Am thinking of taking the insides out and swapping it into my housing. I have rebuilt a number of MC for other cars and the MG does not look that complicated, unless there is a "secret" I'm not aware of at this time. other than the nylon spacer is a bugger to get out I've had little trouble dismanteling the MC. Give me a hint asto where the problem of assembley might be. Any help I get now will be paid back helping other MG owners around.
 
/ubbthreads/images/graemlins/blush.gif Tony--I have just realized I put the reservor on backward. /ubbthreads/images/graemlins/thirsty.gif Would this cause the problems I have in my MGB GT. I can't believe I did that. /ubbthreads/images/graemlins/nopity.gif
 
I thought I was the only one who did such things. There are three types of MG owners, those that have done something like this, those who WILL do something like this, and those who never work on their MG./ubbthreads/images/graemlins/yesnod.gif

Sure hope this is your problem. Please let us know if "fixing" this did the trick.



/ubbthreads/images/graemlins/cheers.gif
 
I use to haul glass out of the Tulsa area. It would be a place I would move to if I left here.
 
I found it the last cup was turned around the wrong way. The MC reservior is no right; the picture I looked at was a Midget and they are oposite of the GT. I will now put everything back together and go and stop and go and stop!!! /ubbthreads/images/graemlins/cowboy.gif
 
The MCs on MGBs with duel line systems are hard to rebuild if you don't do two things. First you must have the proper tools to do the job. No hammers or pliers! Second, if you have never rebuilt one before, get a good set of directions and follow them to a tee! The hardest thing to do on most older ones is getting the plastic retainer out as they have a way of getting stuck because of rust. You can drill two 3/32 holes 1/16th of an inch deep 180 degrees apart in the plastic retainer and use two mechanics picks to spin the disk free. Be very careful not to scratch the piston! Use a little WD40 in the bore. Once the plastic is free, use the picks to gently wiggle the disk out. Don't pry sideways in the disk with the picks as it will break with enough force.From there on just follow the directions. Also before refitting, hone the bore smooth. Small hones, just for master cylinders, are not that expensive.
 
Thanks I'll give it a try. I have rebuilt this one with a kit for a Midget. I now have a B GT kit from Moss and will install it tomorrow. I did not hone the cylinder the first timt and will do it this time. Yes, I have hones as I use to Drag race and repair custom cars. If this does not work I am going to have to purchase a new cylinder. Bleeding the breaks seems to be the hang up now.
 
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