Groaning Front Brakes

[jandarah]

New Rotors/Discs, new fluid, new braided flexible hoses, good quality brake pads (TRW). Pads bedded in to new Discs, but the groaning/vibration still exists on the front brakes when applied. Should I be looking somewhere else, is it normal to Spiders, are the calipers vibrating (even though they seem pretty tight and clamped)??? The car seems to pull up ok when the brakes are "stood on".

AM I MISSING SOMETHING???

[djape1977]

low quality discs.
install old ones for test

[DieselSpider]

Were the rotors brake ready? Some are not sent ready to install and need to be turned first. All new rotors need to be thoroughly cleaned with brake clean to remove the Cosmoline that they are coated with to prevent rust and if you don't that can also cause creaking and rumbling and at times a bit of smoke. Did not see new wheel bearings on the list and disc brakes can groan and rumble when the bearings are worn especially if they were over tightened to compensate for the wear. Were anti-rumble/squeal pads included with the brake pads? If not then you may need to apply the rubber backing plate coating waiting for it to dry before reinstalling the pads.

I bought my rotors locally that were brake ready and were beautifully machined to promote good pad seating and the wheel bearings since I did not know the last time they were serviced I pulled, cleaned, inspected and found to be in great shape so I repacked them putting them back with a new seal. Used the pad back coating which was included with the premium pads to prevent noise and have not had a problem. Since the back rotors were scored and the front still serviceable I put the good fronts in the back after cleaning them and scuffing them putting the new rotors up front. I did thoroughly clean the mounting surfaces of the hubs to ensure that they were smooth and rust/grease free so the rotors lay flat too which if you skip can also lead to rumble and noise.

[RRoller123]

I also made the mistake a few years ago of not thoroughly cleaning the rotors before installation, and had issues as well. If you didn't clean them, it would be a good idea, and a simple matter, to pull the pads, spray down the rotors, lightly sand the pads. Use something like 220 grit paper on a flat surface (table saw top or sheet of glass is good), just to burnish them up/ Put 'em back together and see if that solves the problem.

[jandarah]

Thanks for your suggestions. My main reason for changing the discs was the groaning noise from the old discs (on the suggestion of an older Fiat owner). The new discs were made in Italy and look extremely smooth. The accompanying instructions mentioned that they needed to be cleaned. I thoroughly cleaned the new discs with proper aerosol brake cleaner and also all the other parts. I avoided touching the new clean discs, when installing them. With the pads, I sanded them down a bit, using a figure 8 motion, to get rid of any glazing and unevenness. I used some Copaslip paste on the back of the pads to improve movement and lessen friction and any noise.

No, I have done nothing with the front bearings, they seemed fine, that is, when the wheel is shaken back and forth, when jacked up. As I have only had the car since last March, I have no idea when any maintenance was done on the front bearings, prior to my owning it. Perhaps, I need to get some more bearing grease and carry out an inspection and re-grease. I will have to chase up some new seals.

My next test will be to have my wife with me, so that she can listen to see if it is coming from both sides. Since the car is right hand drive, to my ears, it is coming more from the right side, but it could be coming equally from both.

The fight goes on......

[RRoller123]

Odd, maybe it is the shock absorbers that are actually groaning?

[DieselSpider]

Brake Ready rotors that I have been receiving have a cross hatch finish to them to assist with seating the pads and aren't shiney smooth. Copaslip would only go where the metal guids on the pads engage the slides on the caliper mounts. A silicone rubber spray/coating would be used on the backs of the pads where they engage the piston and stationary outer part of the caliper.

[jandarah]

Thanks again. I am not aware of this type silicone rubber spray, but will chase it up. As for the shock absorbers, again, I know nothing of their history, except that they are not original, but a brand that is the same as a company that does brakes here in Australia (and maybe other countries), Pedders.

[RRoller123]

Can you replicate any of the noise when very slightly pushing the car up and down via the front bumpers?

[DieselSpider]

Thanks again. I am not aware of this type silicone rubber spray, but will chase it up. As for the shock absorbers, again, I know nothing of their history, except that they are not original, but a brand that is the same as a company that does brakes here in Australia (and maybe other countries), Pedders.

If the brake pads do not have anti-squeal shims on them then you need to use brake quiet instead. Most of the better grads of brake pads will include a packet or two in the box with the brake pads.

The packets are usually on the parts counter at the better stores next to the packets of silicon brake grease and many of the better parts stores will check the box of pads for anti-squeal shims or brake quiet and throw a pack or two in at no charge if they find neither.

I use the packets most times unless I have a few brake jobs lined up between all the vehicles in the family otherwise I'll pick up a spray can of the Permatex or CRC brands of Brake Quiet and a bottle or large tube of the silicone brake grease.

http://www.permatex.com/products-2/prod ... 077-detail

http://crcindustries.com/auto/?s=05017

[DieselSpider]

Thanks again. I am not aware of this type silicone rubber spray, but will chase it up. As for the shock absorbers, again, I know nothing of their history, except that they are not original, but a brand that is the same as a company that does brakes here in Australia (and maybe other countries), Pedders.

If the brake pads do not have anti-squeal shims on them then you need to use brake quiet instead. Most of the better grades of brake pads will include a packet or two in the box with the brake pads.

The packets are usually on the parts counter at the better stores next to the packets of silicon brake grease and many of the better parts stores will check the box of pads for anti-squeal shims or brake quiet and throw a pack or two in at no charge if they find neither.

I use the packets most times unless I have a few brake jobs lined up between all the vehicles in the family then I'll pick up a spray can of the Permatex or CRC brands of Brake Quiet and a bottle or large tube of the silicone brake grease.

http://www.permatex.com/products-2/prod ... 077-detail

http://crcindustries.com/auto/?s=05017

[jandarah]

OK, once again. No, the TRW pads did not have any packets of paste with them, I bought them online. Here in Australia, older Fiats, including the Spider are not very common, so getting parts is not just an over-the-counter task at any auto parts store. There are a couple of Italian auto parts stores about and they are online for easy ordering. So, to get even a bearing seal would require ordering and waiting for delivery. It is just a fact of life here. Auto Ricambi in the US does also sell parts into Australia, but unless you are buying a fair bit, the freight charges are rather high. For example, I just ordered some new locating studs for the hubs and they are coming from England. Spiders were never sold in Australia, so they are all imports and rarer than rocking horse droppings!

The TRW pads, made in Europe, I believe, just have a material type of backing which is not very thick and a bit fragile. I will look up the CRC product, as I use that brand for my radio and electronics work and it might be available here. All their products are usually very good. I am sure that there are other brands of brake quietening products available here and will do some searching online. I don't live close to outlets, so online is good for me.

RRoller123, No, I have not tried to replicate the noise by moving the car up and down via the bumpers, but will do so.

DieselSpider, I will check out those links. I know Permatex products are sold here, as I have bought them.

I know I will win in the end, but when that "end" is, I am not sure. I drove my Toyota Landcuiser 4WD today and just noticed how there was no noise or anything (apart from slowing down) when the brakes were applied, both lightly and bringing the big vehicle to a full stop. Please, Mr. Spider take note.

As always, much appreciated.

[jandarah]

Me again.

After doing some reading on the subject, one thing that I did not pay much attention to was the tension on the metal spring clips for each pad. I will have to check them tomorrow to see if they are actually doing anything and they might require some re-tensioning. CRC brake quiet is available online as are stick-on universal rubber shim kits that just need cutting to suit the pads.

[DieselSpider]

I am spoiled here since one or another of the local parts stores have most general maintenance items covered (brakes, shocks(dampers), clutch, muffler, starter, alternator, etc). The rotors were less than $20 each and available in half a day at the local store already cross hatch machined and brake ready.

I on the other hand envy you guys having better access to Isuzu/Holden resources for the 1.8L Diesel Engine that's in my spider. Trying to find just the vacuum pump to slap on the back of the alternator for the power brake system is a major odyssey.

[jandarah]

Well, this could be a good way to trade parts. There are Isuzu diesels coming out of the woodwork down here, big and small. But for Fiats, most have no idea of cars that old, even the model names. One good thing, where I live, is that every drive from here is a 100kph speed limit, with long quiet and sweeping roads. The big problem in the early morning and evenings are kangaroos eating the green grass on the side of the road. Some are very BIG.

I will be checking those spring clips on the pads today. (I have taken the wheels off enough times now to qualify for a racing pit crew).