Pagids

Novice Racer · Post by **Novice Racer** » Mon Jul 16, 2007 12:26 am

Finally fitted my RS 4-2s.

A few issues I need help with.

1) Slack pedal. There has always been a bit of slack in the pedal and you can feel that although your foot has slightly depressed the pedal, there is no feel or sound of the pad on the disc. I had thought that this might be cured by nice warm pads/discs/fluid, but no. Any suggestions (apart from braided hoses).

2) Slight clatter noise on depressing pedal. Just the once, when first placing foot on pedal and does not continue through braking but repeats the next time you try to break. Seems to disappear when pads warmwed up. Almost ss if the pads are loose in the caliper. Is this normal until after some more bedding in (standard bedding in protocol discussd here previously has been followed?

3) Slight regualr tapping sound from front left whilst driving - goes on depressing brake pedal. Similar problem to 2)?

Suggestions appreciated.

NR

dezzy · Post by **dezzy** » Mon Jul 16, 2007 12:56 am

If the pads are rattling in the calipers, you could try some buffers from eliseparts

D

Victor Meldrew · Post by **Victor Meldrew** » Mon Jul 16, 2007 1:23 am

New fluid to improve the feel...

And as for the noise.... you shouldnt be able to hear anything as the revs should be up as you come down the box.... heel n toe man...

..

Oh the buffers do work but I didnt bother, after a bit the rust will build up and take up any slack

robin · Post by **robin** » Mon Jul 16, 2007 9:31 am

Cold fluid can be very contaminated and feel OK, so while I agree that replacing the fluid makes sense, I wouldn't expect a dramatic change in feel for road use.

Crud from the pad does usually jam in the gaps and get rid of the noise.

It's also important that you bed the pads in hard (in my case, that normally just means some track use, but the proper way is some light braking just to heat things up, then repeated braking from 70-30 (or higher), then finally stop from the highest safe speed you can muster, and hold your foot hard on the brake pedal for a couple of minutes).

This may improve the initial slack in the pedal a bit and may cure the clicking.

Cheers,
Robin

Brunty · Post by **Brunty** » Mon Jul 16, 2007 10:03 am

Interesting Robin, most brake manufacturers specifically tell you to not hold any pressure on the brakes once stopped. It can lead to a slightly swollen disc in the area where the pad contact is, and can give a judder from then on.

Infact, iirc, they tell you not to stop at all until the brakes have cooled as much as possible. I just avoid braking and go for a slow drive to cool everything down again.

Brunty

steve_weegie · Post by **steve_weegie** » Mon Jul 16, 2007 10:32 am

From pagids website:

The bedding in/break in procedure should be done as follows:

* Drive at approx. 35 mph (60 kmh) for about 500 yards (solid front discs) to 800 yards (vented front discs) while slightly dragging the brakes (i.e. light brake pedal pressure). This process allows the brake temperature to slowly and evenly build up to 300Â°C (572Â°F).
* Now, if possible, drive about 2200 yards maintaining the same speed without braking. This will allow the pads and discs to cool down evenly. After this cool-down, perform a normal brake application from 35 mph to 0. No panic stops!
* Now, the friction surface has evenly developed friction coal, the pads have bonded with the disc surface, and tensions in the disc materials will have disappeared.
* Only trained master mechanics should perform this procedure before delivering the vehicle to its owner. Do not expect your customer to properly finish your brake job!
* This bedding process is only suitable for the front axle - not the rear. This is due to the brake force distribution of front and rear axles. In order to reach 300Â°C (527Â°F) on the rear pads you would have to drive several miles with dragging brakes. However, in that time the front brakes will be glowing red, overheating and thus destroying the front brakes.
* Final note â€“ donâ€™t forget to clean hubs and check the wheel bearings. Also, the brake fluid should be replaced at least every 2 years.

robin · Post by **robin** » Mon Jul 16, 2007 1:17 pm

One of the lotus techies posted this a long time ago - including holding the pedal on hard once you do the final stop - something to do with ensuring you get a good piston->backplate->pad->disk contact. It may well cause you other problems down the line, like you say.

My disks are at the end of their life, so I may well perform this procedure on them before switching disks to see if there is any "warping".

Cheers,
Robin

dezzy · Post by **dezzy** » Mon Jul 16, 2007 1:23 pm

That's not the Pagid bedding-in procedure I read on their website.

I used this procedure: http://www.braketechnology.com/brakepadbedding.html and then did the compression thing at the end like Robin has described above. I figure that if Lotus recommend that, then they should know what they're talking about.

steve_weegie · Post by **steve_weegie** » Mon Jul 16, 2007 5:21 pm

This is info that i got and used when bedding in my pads recently, but I can see benefits from putting big pressure on the pedal to seat everything correctly too. If that's what the lotus tech suggested then i'm not going to argue, but the pagid page below seems like a good procedure too.....

http://www.pagidusa.com/bedding_in_procedure.htm

Same company giving 2 different procedures from looking at your page dezzy.

Cheers,

Steve

Jamie84 · Post by **Jamie84** » Mon Jul 16, 2007 8:10 pm

while on the topic is there ny significant difference to be had from upgrading to pagids and also upgrading to braided hoses?

Clarkie · Post by **Clarkie** » Mon Jul 16, 2007 8:28 pm

j33ama wrote:while on the topic is there ny significant difference to be had from upgrading to pagids and also upgrading to braided hoses?

Pagids make a huge difference IMHO. The 'bite' of the pads is much better and more progressive. Same braking performance time after time no matter how hot they get. Would recommend putting in some new high quality fluid if upgrading.

robin · Post by **robin** » Mon Jul 16, 2007 9:38 pm

RS42 are worth the money; SBS are a close second, though, especially if you are mostly road with some track use - they do end up wearing out a bit faster (the last 4mm vanishes quickly it seems).

Avoid RS14 for anything but proper race use (or if you have a lot of power). They eat disks!

Steel brake lines not as important as people think but they do make a difference. They do need careful installation and you need to check they aren't fraying from time to time (Kelvin had one fray and burst on the M1!).

Cheers,
Robin

Jamie84 · Post by **Jamie84** » Mon Jul 16, 2007 9:53 pm

apparently the car i am considering buying has pagids and braided hoses

Lack of bite was one thing i noticed when i test drove standard exige while back . Didnt expect them to be as sharp as "normal" cars as they are not assisted , but still thought they lacked a little

albutch · Post by **albutch** » Tue Jul 17, 2007 11:16 am

j33ama wrote: but still thought they lacked a little

RS42s will sort that out

It seems very unlikely that a disc would become permanently warped, I was reading some stuff from a race engineer in the USA who said he had never seen a warped disc. Apparently, bedding in pads is about transferring pad material to the surface of the disc. If your procedure produces high spots then the effect would feel like a warped disc.

I'll see if I can dig out the article.

Post by ed » Tue Jul 17, 2007 11:24 am

j33ama wrote:apparently the car i am considering buying has pagids and braided hoses Lack of bite was one thing i noticed when i test drove standard exige while back . Didnt expect them to be as sharp as "normal" cars as they are not assisted , but still thought they lacked a little

s2 exiges are servo assisted!

But the standard pads are indeed gash compared to the pagids!