1984special

Hey I just bled the brakes on my 84 GSL-SE and they're still kind of soft. I started with the rear right wheel, and made sure to follow all the instructions. Do all 4 wheels need to be off? I only have 2 jackstands. Maybe I'll borrow my friends and re-bleed everything. If I do that, then I'll use synthetic fluid. I think it's Valvoline Synpower? Supposed to have a higher boiling temp than Dot4. All I have now is Dot3. I hope it'll make a diff, but it sholdn't be too big a deal. So anyways, anyone know what else could be causing a soft pedal? It sinks too, when i'm stopped, but not as much as before. *sigh* soft brakes suck...

Thanks for the help.

kettlman

iTrader: (2)

question? did you change your pads and shoe's? or just bleed? i had a soft peddal, bled, and bled. stayed soft, even changed my master. pissed me off cause nothin worked.i had meat on my rear shoes so i didn't change them. then i decided to change them one day for the hell of it. i didn't have as much meat on the shoes as i thought. changed the rear shoes and fixed my softness.( that didn't sound right). good luck.

Rx7carl

Dont use that syn fluid. Its not compatable with regular fluid,so unless you completely drain, flush and remove ALL the old fluid you will have problems. A good fluid is Castrol LMA. As far as your trouble, rebleed. No problem doing one end at a time so do your rear brakes, then the fronts. Check for a possible bad (soft/swelling) hose.

jimmdog

Check the caliper pins, usually one of the slider pins will seize and cause the caliper to swing at an angle. This will give you one hell of a soft pedal. Take the wheels off, get some one to pump the pedal for you and look at all of the calipers. If you see one swinging thats your problem, anti seize all of the pins and sliders.
As far as brake fluid goes flush it out completely I use ATE super blue racing just my prefrence Good Luck

MarkPerez

carl's got it right. to use the dot 5 all the rubber in the master will need to be up-graded as well as the hoses.
A soft and sinking peddel is hose swell or a leak inside the master. Make sure the booster hose is not cracked or leaking vacum too. Also check all the hardlines for a ding. On the -SE's when the brakes are good. You know it i have yet to feel mine fade.

MarkPerez

carl's got it right. to use the dot 5 all the rubber in the master will need to be up-graded as well as the hoses.
A soft and sinking peddel is hose swell or a leak inside the master. Make sure the booster hose is not cracked or leaking vacum too. Also check all the hardlines for a ding. On the -SE's when the brakes are good. You know it i have yet to feel mine fade.

Metallic_rock

I've always been taught to bleed closest to the master and then work back, so that would be front to back. This makes sense to me because you would be getting the air out closest to the master cylinder first and then you'd work further from it. If I'm off here, please let me know!!

GavinJuice

When you bleed the brakes start from the RR move to the RL the FR and finially the FL. Everytime before you open the valve have someone pump the brakes 2 good times, not too hard, then crack open the valve and let er fly. Do that at least 2 times per wheel. continue following the RL the FR and finially the FL. Another problem could be your wheel cylinders. If your bleeding your brakes then maybe you replaces pads/shoes? If you did pull off your drums and see if you have any leaky wheel cylinders.

1984special

No I didn't change my pads yet... And I got no shoes, all disc brakes!

This is what I'm using right now.
Pyroil Dot 3

This is what I want to use. SynPower High Performance Synthetic Brake Fluid

It says


So I guess I'm gonna rebleed and check for swinging calipers, swelling or cracked hoses/lines, or a vacum leak. How would I anti-seize a seized caliper? (noob guess: WD-40?) x_X How would I check for a vacum leak? I gather the car has to be on... and I'd be looking near the master?

Thanks for all the help!

Rx7carl

Hmmmmm. Ah I was thinking Silicone fluid not Synthetic, sorry, carry on. Mark was thinking the same thing. DOT5 is silicone fluid.

And Metallic, Gavin is right, your going backwards.

inittab

remove the calipers from the slider pin, clean them up real good then use high-temp synthetic brake grease. The calipers should move freely on the pins.

bliffle

Yeah, I got the soft pedal on my 83. Pedal goes to the floor while waiting for a light to change. I'll try bleeding it, but I bet I've got leaky slaves. I put in new pads/shoes all around last summer.

B

Rx7carl

biffle, the pedal creeping to the floor sitting at a light is a bypassing master cyl (unless you have a leak).

bliffle

You mean it's blowing by the piston? Sounds like a new master cyl solves the problem.

B

Rx7carl

Yup, the fluid is seeping past the seals back to the reservior. Time for a new master.

ostryjak

I took ownership of an '82 RX7 2 days ago and the brake pedal sinks to the floor while stopped at a light. It is a most peculiar sensation. I have owned many many older cars with many many brake problems that I have had to fix. However it is ONLY on this RX7 that I have experienced such an odd sensation. My point ?. Given the # of responese and queries in this thread I would say that this is particular to RX7's and yeeees - I would concur that the problem is likely seep by on the master cylinder rubbers. Most other vehicles with failing master cylinders will however maintain their pressure once the rubbers inside are locked up against the wall of the cylinder. When they do not the master cylinder simply does nothing at all and you have no brakes at all.

My 2 cents worth.

Rx7carl

Hi, actually Ive had that happen on other cars so not an exclusive 1st gen problem.

zookeeper

Me too, and a good master cyl rebuild or replacement takes care of it.
My 84 SE's just starting to do it and I've got a nice new master cyl sittin in the garage just waiting for me to quit being lazy and install it. I should have it in in a couple of years