Replaced front calipers- can`t get full pressure back

[ben1be]

FJ 62
I replaced the front calipers and pads. I did`nt have a pressure problem before, pedal resistance was o.k. I`ve bled each wheel and the sensor over the axle twice. At each point I get clear fluid, but never get prpoer pressure, so its not that it deteriorates after bleeding.
Pedal goes to the floor and I get some brake there, but if I pump it I get pressure and brakes work fine until I fully release the pedal. So I can accelerate along and using left foot pump brake and stop normally.
No apparent leaks.
Any ideas what`s going on?

 

[NocalFJ60]

Did you bleed all four calipers? Start at the one farthest from the master cylinder. Also I saw a test awhile back about checking the master cylinder.

 

[ben1be]

I did bleed all four wheels starting driver side rear, but I have`nt bled the m/c and I think I`ll give that a shot.
thanks

 

[Gumby]

try tapping the calipers while you're bleeding them. I've seen a lot of four piston fixed calipers that trap air bubbles.

 

[schaats]

IMHO, I want to suggest gravity bleeding of califer and master cylinder bench bleeding.
Almost case, brake pressure problem is caused by not enough bleeding, you know.
Faulty master cylinder cause pressure problem also in many case but in your case I suppose problem is caused by air bubble in your hydrolic system.

Oh, Min Seok

 

[ben1be]

Thanks for the ideas.

I bled the M/C and that gave me a little more brake. Why does pumping the pedal firm up the pressure in the system? Is it compressing the air that`s in there?

Mike

 

[schaats]

If you must pump several times to get firm braking, it seems M/C doesn't operate well.
Check like this,
1. Pump several times to get firm brake feeling.
2. Hold pedal and check whether pedal goes down or not.

If pedal goes down to floor slowly, it means your M/C has problem or there might be leak in hydrolic system.

Good luck !

Oh, Min Seok

 

[baldredhead]

Thanks for the ideas.

I bled the M/C and that gave me a little more brake. Why does pumping the pedal firm up the pressure in the system? Is it compressing the air that`s in there?

Mike

yes, the air bubbles get compressed then there is sufficient pressure to move the pistons.

your description is classic air in the lines, sometimes it takes a lot of bleeding. since you have a 62, try bleeding the LSPV too. it's above the rear axle, bleeder is on the driver side. i think it's the first thing yo're supposed to bleed.