420A Spongey brakes no matter what.

[96WhiteEclipse]

As the title suggest my brakes are spongey.

I bled them 3-4 times without any air coming out. This led to me believing I needed a new master cylinder. I bought the master cylinder, I did a bench bleed, put the part in the car, and finally I bled the brakes in order of

Passenger rear
Passenger front
Driver rear
Driver front

I read another post about a guy with the same problem, he said he resolved it and that there was air somewhere in the system that did not want to get out. I’m thinking it’s possible.

I will keep bleeding the breaks and this time do the order of

Passenger rear
Driver rear
Passenger front
Driver front

Is there any tips or had anyone had this problem too and if there is air that doesn’t want to come out what should I do?

*also to mention, the brakes seem to function a bit better when applied at speeds above 60 mph.

 

[luv2rallye]

For difficult air bubbles bleed: With the bleeder valve closed on brake caliper, pump brake pedal really hard and fast 8 times. Then on final pump, hold down while helper opens bleeder and then closes it (of course have bleeder valve on hose in jar of brake fluid, can be used fluid). Repeat until no air bubbles.

For brake caliper bleed order, always do the furthest one from the brake master cylinder first and work back to the closest. So it will be RR, LR, RF, LF.

 

[TerminalTalon]

For difficult air bubbles bleed: With the bleeder valve closed on brake caliper, pump brake pedal really hard and fast 8 times. Then on final pump, hold down while helper opens bleeder and then closes it (of course have bleeder valve on hose in jar of brake fluid). Repeat until no air bubbles.

This is really the only way. I’ve always done 3 pumps, hold and crack the bleeder.

 

[FIBA M - EC17PSE]

you cannot bench bleed these masters as they are an open system. so as soon as you release you allow air inside again.

What I did on mine when I was upgraded years ago to brembos was i looped the prop likes back into the res pot and basically self bled the master on its self and once no more bubbles came out then they held the pedal down so the master is CLOSED and re attached it to the prop valve again, then the bleeding process begun. first time and no issues,

the annoying thing on these masters is the open design so they dont bench bleed and only lubricate really. you still have to bleed the masters on installed. some vehicles have bleed ports on the masters for this to help but mitsu dont offer this so you have to do the long winded way.

 

[96WhiteEclipse]

you cannot bench bleed these masters as they are an open system. so as soon as you release you allow air inside again.

What I did on mine when I was upgraded years ago to brembos was i looped the prop likes back into the res pot and basically self bled the master on its self and once no more bubbles came out then they held the pedal down so the master is CLOSED and re attached it to the prop valve again, then the bleeding process begun. first time and no issues,

the annoying thing on these masters is the open design so they dont bench bleed and only lubricate really. you still have to bleed the masters on installed. some vehicles have bleed ports on the masters for this to help but mitsu dont offer this so you have to do the long winded way.

What do you mean in this section “ i looped the prop likes back into the res pot and basically self bled the master on its self and once no more bubbles came out then they held the pedal down so the master is CLOSED and re attached it to the prop valve again, then the bleeding process begun.” There’s a lot of terms I’m not familiar with

 

[FIBA M - EC17PSE]

What do you mean in this section “ i looped the prop likes back into the res pot and basically self bled the master on its self and once no more bubbles came out then they held the pedal down so the master is CLOSED and re attached it to the prop valve again, then the bleeding process begun.” There’s a lot of terms I’m not familiar with

so I removed the 2 lines going into the prop valve from the master cylinder and placed BOTH into the res chamber, then i self bled the master and once no more bubbles came out i had the helper close the valve by putting the pedal down as normal and i then put the lines back onto the prop valve! once done i then continued to pump till the fluid could not drain any more from the res chamber and then bled the brakes as per normal, its the most ideal way on the stock mitsu masters

 

[sicawd]

Thanks for the info, help me solved my issues.

 

[96WhiteEclipse]

So I have a 2g Eclipse GS. The brakes have given me trouble since day 1 of owning the car.

Since owning the car the brakes have worked, they stop the car, but I feel they should be working better than they do.

I’ve bled the brakes in order of
Passenger rear
Driver rear
Passenger front
Driver front

I had one person pump up the petal then they push the brake and I open the bleeder valve until they tell me the brake petal hit the floor after that I close it then tell the person pumping to let off the brake. After I do this on all the wheels the brakes feel incredibly weak, UNTIL I drive it for awhile.

This car doesn’t have ABS and yet it still can’t lock up the tires very well. The brakes seem to work better at higher speed when it feels like the pedal actually gains some pressure. I’ve driven other cars and you barely hit the brakes for them to work but for my car it’s usually nearly pedal to the floor for what most call normal braking.

I replaced the master cylinder, and all the brakes (rotors, pads, calipers, and soft lines) *all OEM.

I’m not one to take my car to a certified mechanic but it might be time. I’ve tried everything but nothing works. Any advice would help. It’s a safety risk that I don’t want to keep happening.

 

[spyderdrifter]

When you replaced the master cylinder, did you bench bleed it prior to installing? Have you checked for leaks in your hard lines? It really sounds like your brake system still has air in it, or leaking into it.

 

[FIBA M - EC17PSE]

Stock calipers are not strong and its a heavy car also! You mention stock pads so mitsu pads I'm assuming vs parts store! Had me wondering if you might be needing heat into the pads to work well but should be ok on stock pads.

As for bleeding you DON'T want the pedal to hit the floor! You crack it for a second then close it off. The pedal to the floor can ruin the piston seal inside and cause problems. So NEVER bottom this out! So get them to pump it a few times till hard, then get them to hold, and then crack the nipple a sec, then close. Re pump, hold and crack, repeat then move around and go around a second time to be sure.

If the master does have trapped air and its possible also considering its been bottomed out then you need to self bleed the master on its self (loop lines into res pot and pump till no bubbles come out) they either bleed good or don't so depends how lucky the person is.

Where you start and finish is all ok and normal on a stock prop system so that's good.

Also just a check that the pistons and sliders on all calipers are free moving and not jamming at any point as they warm up (as you said they work after a while) so could be jammed when cold and loose when warm

 

[luv2rallye]

Another possibility that fits your symptoms is a bad brake booster.