Poor braking capacity after bleeding brakes

Macen · Post by **Macen** » March 25th, 2005, 2:21 pm

Today I installed my Goodridge stainless steel brake line kit. Installation was not that hard, and it went fine without any big problems.

I also installed Speed Bleeders.

Afterwards I bled the brakes until I couldn't see any air bubbles. Then I took the car out and felt that the brakes only worked with the pedal fully pushed, and braking capacity was bad. I read afterwards that pushing the pedal to the floor when pumping the pedal is not good. Though that's what I did. My friend did the same with his Honda CRX, and there was no problem at all.

I know that the brake fluid level was just below half full when I refilled it.

What can be wrong? Bad master cylinder seal, or just air bubbles in the system?

I also changed the clutch line, and it works like a charm. No problem at all.

Grants · Post by **Grants** » March 27th, 2005, 7:31 am

Does the braking get better if you pump them a few times? If so you need to bleed them again.

Macen · Post by **Macen** » March 27th, 2005, 10:30 am

No, it dosen't get any better. Must be bad seals in the master brake cylinder.

When bleeding, should the ignition be switched on so that the ABS system can apperate?

Does anyone know what a new master brake cylinder costs in USA or Canada? Here in Sweden it is very expensive. All Mazda parts are. For example a new ABS rear sensor costs $530.

jschrauwen · Post by **jschrauwen** » March 27th, 2005, 12:49 pm

'92Manual page P-7, does not stipulate that the ignition has to be on or not. It does say that you must never let the reservoir level go below the min level and to keep it at least at the 3/4 mark. You must also start your first bleeding process from the farthest point working toward the closest. If you were relying strictly on the speed bleeder, I would recommend getting a buddy for your next bleed attempt and hold off looking at buying any replacement parts until the bleed issue has been completely exhausted. Braided SS lines are a bit more of a b*tch to bleed than rubber lines, probably the one and only downside to them, but the benefits make it all the worthwhile. Try it again Macen, with a buddy this time and let us know. As a side note, once lines are installed the max pressure capable of the SS lines is extremely high and you don't want to be trying any "Schwartzeneger" pedal pushing for fear of overloading the capabilities of the master/slave cylinders, FWIW. Hope this helps

Macen · Post by **Macen** » March 27th, 2005, 1:55 pm

Yeah, I followed the manual regarding the bleeding. I had a friend pumping the pedal.
I will buy some cheap brake fluid and bleed the whole system again later.

Taras · Post by **Taras** » March 27th, 2005, 3:11 pm

I think leting your fluid reservoir go below half is a definite issue here. You must never let it fall below minimum and as John pointed out it is best to kept at max when bleeding.

Macen · Post by **Macen** » March 27th, 2005, 3:14 pm

Maybe...
Though I can't pump up any pressure.

mitmaks · Post by **mitmaks** » March 27th, 2005, 3:16 pm

maybe use regular bleeders and bleed brakes with 2 people, starting in the back working towards master cylinder, ie right rear wheel, left rear, front right, front left. make sure you dont run out of fluid in reservoir, keep it topped off

jschrauwen · Post by **jschrauwen** » March 27th, 2005, 3:52 pm

Macen wrote:Maybe...
Though I can't pump up any pressure.

OK, mixed messages here. First you said that there wasn't much pressure when you went out for a test ride, and now you cannot pump any pressure. Are you saying that you cannot get any fluid out of the bleeders either?
It's possible that you may have introduced air into the system by mistake when not topping off the reservoir frequently enough. When bleeding manually with your bud, I don't believe there is any harm to pumping the pedal a couple of times, then holding it while you crack open the bleeder valve and drain and then close again. If air did get introduced into the system because the reservoir was allowed to go too low than you're looking at a very lengthy bleed process because those air bubbles have a long way to travel to get to the bleed nipples. Don't think you can do this with cars, or at least I've never heard any one try it but part of my bleed process for my motorcycle is that I bleed it from the banjo fitting right at the master cylinder. The reason being is that it's easier for air bubbles to travel up rather than down. Problem is it can get very messy (lots of shop rags needed) but it's really quick. So I don't know if anyone's ever tried that with an MX. If all else fails and you have enough pressure in the system to get the car to the shop, they'll have a fluid evacuation system that will draw (suck) all the fluid out each line, and rather quickly too. It doesn't take long and they shouldn't charge that much. That will be my route when it comes time for me to install braided lines, it's just that much quicker and IMO better. Hope this helps.

Zoso124 · Post by **Zoso124** » March 27th, 2005, 3:59 pm

Just rebleed it, I've never heard of it being harmful to push the pedal to the floor, been doing it for years with no problems. Good Luck, let us know how you end up.

Macen · Post by **Macen** » March 27th, 2005, 4:06 pm

Yeah, I have to push the pedal fully to get any braking capacity at all. And yes, the reservoar limit was below low

Thanks for the replies. Will try to rebleed again and see what happens. If it dosen't get better, I will leave the car to the car shop.

Macen · Post by **Macen** » April 1st, 2005, 2:38 pm

Finally I've got great braking capacity!
I rebled the brake system with standard ATE brake fluid. Now the brake feel is very direct and "agressive".
The Goodridge SS brake lines are really good! Though I didn't got them with midsupport, so I had to mount them on the strut with tape. Dunno what I should use to mount it "correct".

Now I only need to replace my discs with Brembo ones and my pads with Ferodo Premier

jschrauwen · Post by **jschrauwen** » April 1st, 2005, 7:19 pm

Outstanding Macen, good stuff!!. I guess the old rubber lines had hanger mounts built in. Not sure as to how to fix except perhaps instead of tape you could use 2 strong zip ties looped together from the strut until you find a more permanent fix. Performance shop may have some ideas. I vaguely remember an old post where someone had to drill out the hanger mount for the SS line but I'm not 100% sure. Hope this helps.

RizzeRocket · Post by **RizzeRocket** » April 4th, 2005, 9:45 pm

It must look funny from underneath looking at the tapes trying to hold up ur brakelines

but make sure u wont try to weld em on

Macen · Post by **Macen** » April 5th, 2005, 2:21 am

Hehe, yepp, it looks a bit funny.
What have you guys used when you replaced your lines to hold em at the right place?