1989 2.7 944 Brake Pads won'™t fit!

[IanDyke]

1989 2.7 944 Brake Pads won't fit


OLD PADS = TEXTAR T400 FF (944 351 941 01)
NEW PADS RECEIVED = PAGID T1071 (944 351 951 02)

Hello All,

I recently ordered a new brake pad set from design911 but I have experienced some problems fitting them. There appears to be only one option for this year with the single piston caliper but the outer pad appears to be too thick. The lug on the caliper needs to be located on the outer pad before the caliper can be fitted but I can't assemble it since there is not enough space for the disc in the caliper housing. The piston location makes no difference since this only touches the inner pad (and at this stage in the rebuild it isn't fitted). It seems that the inner and outer space for the pads is different.

Does anyone know of any other pad specifications for the 944S or any similar experiences to explain this issue?

I will take some photos and post these later

Cheers

Ian

 

[Eldavo]

Only glancing at this but the 944S and 944 2.7 pads are different I believe.

 

[944 man]

The calipers are the same. The usual issue with a 2.7 is finding parts as the model doesnt appear on any North American-derived fitment lists, as they didnt ever see the model (ie 8v NA parts ened with the 2.5l '87MY car).

 

[IanDyke]

I have managed to take a photo of this problem. With the outer pad located on the positioning lug on the caliper there is no space to move the disc into position. I have measured the space for the outer and inner pad and they are different!

 

[924nutter]

I'm sure you mean the caliper isn't screwed on. The part number you quote for the new pad is correct, and I thought I recognised it because it is the same as the front pad for the 924 Turbo but the cailper is different, probably because of the difference in offset, so have you tapped the sliding half of the caliper so that it is fully expanded? Bearing in mind the active side is bolted to the strut that slide has to go back a fair way, and because it has been a long time since the caliper was opened this wide crud and corrosion build up making you think it is opened wide when it isn't. Take the offending pad out and bolt the caliper back on then give the place where the two metal parts slide over each over a treatment with plus gas or something but dont get it on the rubbers or the friction surfaces. If you haven't already, give the caliper some firm taps with a copper hide mallet top and bottom but dont hit the brake pipe or hit the caliper like you are trying to break it off the strut. I hope you will find it will open out further and let you get the pad in without removing the caliper. Having checked on P.E.T. you have the same calipers and pads as my old 944s and I certainly remember going out at lunch time during a track day at Castle Combe, buying pads from a motor factors, and fitting them at the track without taking the caliper off and all in about two hours from leaving the track to getting back on the circuit including driving around to bed the new pads in. I mention this as encouragement for you to persevere as if you have the right pads they must fit unless the pagid pads are too thick but as we haven't had loads of people on here and presumably other forums saying their pads wont fit, they must be correct unless you are the first of many to flag it up. I'm sure you'll get to the bottom of it.

 

[Veerzigzag]

924nutter is accurate and correct as ever. My experience: when I changed front pads on my '89 2.7, I found that the two halves of the calliper were not sliding fully. Careful application of copper grease using a toothpick to get a tiny amount into the right place, and some time spent sliding them backwards and forwards eventually got them working correctly, to their full extent. Then I found that I had to clean the stub that fits into the back of the pad so it seated fully. Then it just fitted over the disk.

 

[IanDyke]

Thank you for all of your helpful comments. Looking at the photos this does appear to be the problem, with the sliding caliper not moving out to allow enough room for the pads and disc. I had previously checked the piston position but didn't realise that there was also a sliding part to the caliper too. I will check this on the car later and hopefully this will solve the problem.

Thanks again

Ian

 

[Veerzigzag]

Another thing I noted on my 2.7 was that it is not too difficult to split a calliper into its two parts but an absolute sod to get it back together because of the big wire spring.
Just keep it whole and spend time levering it back and forth with an increasing amount of copper grease in the joint (but nowhere else) and it will eventually be OK. The copper grease will keep it working properly too, ready for the next pad change.
The other job that is an absolute swine is replacing split rubber boots over the pistons, but essential if they are split of course.

 

[924nutter]

Two years ago I bought caliper repair kits for the 924t in preparation for my forthcoming 220 hp 924 upgrade, and they were under £9 per caliper, and offset notwithstanding I would hazard a guess that the kit is the same for the 944. Getting the bastad wire spring out of the caliper is a swine.

 

[Mike_Pollock]

Yep - to all of that!

 

[IanDyke]

An update...The sliding caliper mechanism is now moving on both hubs and the outer pads fit with the caliper in place. I now understand why I needed to remove the caliper previously to remove the outer pads but I wanted to replace the discs anyway and so this wasn't an issue.

Just one query, the piston isn't retracting enough to push in the inner pad. Does anyone have any tips since I don't want to risk damaging the piston with too much force or using something that will score/burr it?

 

[Mike_Pollock]

I find a large pair of plumbers grips work well.

Usually I find the "push - leave a couple of minutes - and try again" method usually works, also take the top off the reservoir helps.

 

[vitesse]

I usually use a G clamp with great success.

 

[924nutter]

Usually I use the old pad as a protector for the disc surface, and lever the piston back with my fitters pry bar which has a 45 degree cranked end and a half sharp chisel point about 1 1/4" wide. If you need much more than this to move the piston, the chances are that the seal has gone hard and you may experience binding. The seal projects from the housing ever so slightly, and forms a very good seal around the piston that can withstand 2500 psi which is a typical pressure in a braking system. The tiny part of the square section seal that projects, distorts and moves with the piston. when the seal can distort no more the piston slides through by a small amount which accounts for wear. With me so far? When you release the brakes the seal regains its shape and it is this retraction of the seal that eases the piston away from the pad. When the seal gets hard, the distortion can no longer ocur but the piston still slides through, and then stays put causing the familiar binding. Just FYI as you hadn't mentioned that your brakes were binding.

 

[IanDyke]

Thanks to everyone for your help. The pads and discs are now fitted and the 944 is back on the road! The caliper pistons just needed a little encouragement to allow enough clearance for the new inner pads to slot into place.