| ausmini https://www.ausmini.com/forums/ |
|
| drum brakes https://www.ausmini.com/forums/viewtopic.php?f=2&t=67560 |
Page 1 of 2 |
| Author: | Ryan1980 [ Thu Dec 09, 2010 5:29 pm ] |
| Post subject: | drum brakes |
Hi, I'm trying to get the brakes working on the clubman i'm restoring. Basically when i push the brake pedal, it goes straight to the floor - no pressure on it at all. I changed the master cylinder and bled all the lines. also adjusted the wheel cylinders. Any ideas? Ryan |
|
| Author: | ryan [ Thu Dec 09, 2010 5:35 pm ] |
| Post subject: | |
Is the master cylinder connected to the pedal 
Seriously though, check: - rubber hoses to each wheel - Check for any leaks (is it holding fluid?) - check the wheel cylinders for leaks Before you put the new master in, did you check the seals in it? I have heard of new MC's having dodgy seals and/or no seals at all. |
|
| Author: | VulcanBB18 [ Thu Dec 09, 2010 5:46 pm ] |
| Post subject: | |
What happens if you pump the pedal a few times - does it firm up? cheers Jacob |
|
| Author: | Irish Yobbo [ Thu Dec 09, 2010 6:20 pm ] |
| Post subject: | |
Put visegrips on all four of your rubber hoses. If the pedal still drops, it's a master cylinder or bias valve problem. Have you got a late clubby with the tandem cylinder? I had a similar problem where the pedal sat too low - it worked, but it was almost at the floor. It turned out to be the bias valve - I just bought an o-ring set from repco, changed those over in the valve and gave it a clean, works fine now. You can check the master cylinder by itself by getting a couple of small bolts and putting them in instead of the brake lines. If the pedal still goes down, it's stuffed. Oh, and also check the pedal, clevis pin and clevis pin hole. Sometimes the hole can wear and give a lot of movement. |
|
| Author: | superSeven [ Thu Dec 09, 2010 6:34 pm ] |
| Post subject: | |
Irish Yobbo wrote: Put visegrips on all four of your rubber hoses.
If you do this please put something between the vise grips and the hose to prevent damaging the hoses. Better yet, get some brake line clamps which wont damage the hoses, they are cheap at supercheap etc. |
|
| Author: | Ryan1980 [ Thu Dec 09, 2010 6:50 pm ] |
| Post subject: | |
Ithanks for all your help guys. I tried bleeding them one more time. If i pump the brakes it does firm up a bit , but the first pump or 2 it goes to the floor. I also tried to adjust the wheel cylinders. Actually now the car feels like the brakes are on all the time - I can't push the car even with the brake pedal off and handbrake off! |
|
| Author: | Ryan1980 [ Thu Dec 09, 2010 6:56 pm ] |
| Post subject: | |
by the way , what is the bias valve? sorry im a new to all this haha |
|
| Author: | Wombat [ Thu Dec 09, 2010 7:00 pm ] |
| Post subject: | |
Do you have twin leading shoes ? -- if so there is a second bleed nipple tucked up out of sight that can trap air |
|
| Author: | Ryan1980 [ Thu Dec 09, 2010 7:04 pm ] |
| Post subject: | |
no idea mate... master cylinder is just standard i think |
|
| Author: | rathcoole [ Thu Dec 09, 2010 7:18 pm ] |
| Post subject: | |
Did you prime the master cylinder with brake fluid on the bench before you fitted it? cheers Kevin |
|
| Author: | Ryan1980 [ Thu Dec 09, 2010 8:20 pm ] |
| Post subject: | |
nope? just fitted it up, and put some fluid in... |
|
| Author: | Irish Yobbo [ Fri Dec 10, 2010 4:49 pm ] |
| Post subject: | |
Quote: nope? just fitted it up, and put some fluid in. You really need to fill the cylinder with fluid before you attach the pipes. The pedal usually won't travel the entire length of the cylinder, so just attaching it can leave air in there. Whack it in a soft-jawed vise, put some fluid in the reservoir, and push the plunger all the way to the end. Then block off the pipes, and slowly release the plunger back to normal - this will suck fluid in from the reservoir into the cylinder. You might need to do this a few times - I've done it by myself, but it would be much easier with someone to help you. The idea is to fill the cylinder with fluid and remove all the air. I reckon this might solve your problem. Quote: by the way , what is the bias valve? sorry im a new to all this haha
The bias valve reduces the braking pressure to the back brakes, since you want most of your braking power at the front. On all braking systems there will be a little valve between the master cylinder and the back brakes. If you have a tandem master cylinder (which has two outputs), both the outputs will lead to a 5-way valve that's mounted on the bulkhead. It was the 5-way valve that I had problems with. When wombat asked if you had twin leading shoes, he was referring to the front brakes. The back brakes have one adjusting nut, the front brakes have two - one for each wheel cylinder. I didn't know about the second bleed nipple, but I suppose it attaches to the 2nd wheel cylinder. |
|
| Author: | Ryan1980 [ Tue Dec 14, 2010 6:10 pm ] |
| Post subject: | |
ok got under the car again today to have another shot at this. It would appear i do have twin leading shoes, as there are 2 adjustment nuts. However i can only see one bleeding point, is there definetly 2? The front wheels will barely move and i can not turn the top adjustment nut's on both front wheels - in fact i broke an 8mm spanner trying to turn one! Is something wrong? I'll try some wd40! Also whilst attempting to bleed the brakes again one of the rear blake bleeding screws snapped off - im guessing this means i need a new wheel cylinder (and probably need to start bleeding from scratch again) This car is going to send me insane. |
|
| Author: | VulcanBB18 [ Tue Dec 14, 2010 6:46 pm ] |
| Post subject: | |
You need to take a systematic approach to it or you will be forever chasing your tail. Check ALL the cylinders, front and rear. Peel back the rubber boot on them a little, if there is fluid in there, they are gone and need replacement or a kit through them. If the bleed nipple sheared off, then most likely the cylinder is gone too. Replacements are cheap. Satisfy yourself that all the cylinders are ok, then put all the drums back on, adjust up (you need only adjust until the shoe is *just* dragging on the drum, if you can't move the wheel it's too tight!) and bleed the system. If you want the really easy way, just crack the nipple and let it dribble (messy but can be cleaned up ok), starting from the rear left first, then rear right, then left front then right front. Keep an eye on the master cyl to make sure it always has plenty of fluid. From memory there is only one bleed nipple on the front, the two cylinders are closely interconnected anyway. cheers Jacob |
|
| Author: | GT mowog [ Tue Dec 14, 2010 6:49 pm ] |
| Post subject: | |
Ryan1980 wrote: ok got under the car again today to have another shot at this. It would appear i do have twin leading shoes, as there are 2 adjustment nuts. However i can only see one bleeding point, is there definetly 2?
The front wheels will barely move and i can not turn the top adjustment nut's on both front wheels - in fact i broke an 8mm spanner trying to turn one! Is something wrong? I'll try some wd40! Also whilst attempting to bleed the brakes again one of the rear blake bleeding screws snapped off - im guessing this means i need a new wheel cylinder (and probably need to start bleeding from scratch again) This car is going to send me insane. There is only 1 bleed nipple per wheel. The front adjusters work on a cam principal, not a screw. So only a small turn makes a big difference. They can and do seize up. There are two of these per wheel on the fronts. The rears have only one and these are a screw adjuster. When adjusting the front (after you get the adjusters working) turn the adjuster in the same direction of foward travel of the wheel itself. This stops them (or at least is supposed to  ) from un-adjusting. eg, when going in a forward direction, if that wheel turns anti-clockwise, turn the adjuster the same way.
The best fix would be to fit discs. |
|
| Page 1 of 2 | All times are UTC + 10 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|