PNM FRONT BRAKE UPGRADE KIT

[lotuslover1]

Hi guys,i recently purchased the font disk/caliper upgrade from PNM.I have noticed that on the caliper,one of the pistons is bigger than the other two,does anybody know if it sits at the top or bottom of the disk when installed?

As it doesnt mention it in the instructions,or have any markings on the caliper itself.Have tried emailing PNM but no response yet.

regards

[Rambo]

Brake fluid bleed screw should be at the upper most point when fitted.

[lotuslover1]

Instructions says there are two nipples,but to just use one of them

[yeller77]

From a couple of sources:

Quote

When we are talking about multi-piston brake calipers, some are directional and some are not.  One trick brake caliper manufactures use to help get better performance is to use staggered caliper piston sizes.  This means if you have a 4 piston caliper, 2 pistons will be slightly smaller in diameter than the other 2.  This is done to help minimize tapered brake pad wear.  Because of the different size pistons, these calipers are directional. Therefore you want to ensure that as the rotor rotates through the brake caliper it is passing the smaller diameter pistons first then the larger pistons last. 

Quote

Brembo's calipers are directional, due to the use of sequential piston sizes. The leading pistons are smaller in diameter in order to combat uneven wear of the brake pads. Upon close examination of the caliper, you will find a small arrow cast in place which denotes the direction of disc rotation. Additionally, when mounted on the vehicle, the bleed screw(s) must be at the top of the caliper.

Yours probably don't have an arrow as they can be flipped side to side, hence the two brake bleeders. Hopefully the above gives you some guidance on orientation. Bigger piston trailing. Nice kit. Merry Christmas.  

[lotuslover1]

cheers buddy,that makes sense.Merry Christmas to everybody.

[DanR]

An easy way to remember is by looking at the physics of what's happening. Braking produces gasses and debris. So what comes off the first or leading piston affects the ability of the second, trailing piston, to press with the same force. So by making the second bigger it regains the ability to press through the gasses and debris and match the pressure of the leading smaller piston.

Is your v8 blue?

[lotuslover1]

its a burgundy colour

[DanR]

Gorgeous.

[Chillidoggy]

If you can wait until next week I can have a look at mine for you.

[CHANGES]

@lotuslover1Small piston should lead .. 

[lotuslover1]

thanks

[lotuslover1]

hi guys,i fitted the brakes this morning(ignore the AP decal) they fit straightforward ,and PNM have been very helpful.Just got me thinking,how are the pads pushed off the disk after the car comes to a stop?The BREMBOs have clips,but what do the PNM calipers have?

[DanR]

Those are the anti-rattle springs. The pads retract by the distortion and recovery of the square seal between the caliper body and the pistons whenever the brakes are applied. It's a minute amount but enough to stop drag. That same action also allows the piston to extend out and compensate for pad wear.

Nice brakes.

[mike_sekinger]

Are these genuine AP calipers supplied by PNM?

[lotuslover1]

no just $10 decals i put on

[lotuslover1]

hi guys,just an update on the situation with the brakes.The brake pedal feels spongy so i believe there is air in the system.I have tried the gravity method,vacuum and second person pumping the pedal method.There are no leaks so i think air is still in system.I have bled them in sequence furthest to nearest and think air might be in the ABS system.

Does anybody know if those two marked points are bleeder screws?

 

cheers

[sailorbob]

For the KH EBC 430 see this post:

https://www.thelotusforums.com/forums/topic/96690-bleeding-kelsey%EF%BB%BF-hay%EF%BB%BFes-%EF%BB%BFabs%EF%BB%BF-brakes/#comment-795486

For the KH EBC 415 look two posts above it.

[Patmandu]

Did you ever get the brakes sorted? I'm thinking about ordering the same kit and haven't been able to find any reviews of it.

[lotuslover1]

hi,yes brakes sorted,i over complicated things by thinking it was the kelsey system.It was air in the lines,used the gravity feed method and the are working so good now.Very happy.The only downside is all the brake dust that builds up on the alloys.

[andyblackman777]

How is the brake feel? I've heard the pedal travel is longer with these?? 

Also where did you get your wheel spacers from??

Cheers

Andy

[lotuslover1]

hi

yes slightly longer but the bite is killer,it stops on a dime.Im very impressed.The spacers were purchased from Germany