Brakes Pulsing - Page 2 - PeachParts Mercedes-Benz Forum

Jareb · #16 11-23-2015, 07:36 PM

85 300TD....I don't think this year had ABS?

leathermang · #17 11-23-2015, 07:58 PM

I just could not think of any other pulsing which might be involved given what you have already done...

dude99 · #18 11-24-2015, 12:17 AM

Abs was an option in 1985. Post a picture of the right hand side of your engine bay for us if you can.

leathermang · #19 11-24-2015, 12:28 AM

Quote:

Originally Posted by dude99

Abs was an option in 1985. Post a picture of the right hand side of your engine bay for us if you can.

Driver or Passenger side ? and what does ' it ' look like ? Is it on the fender or firewall ?

Jareb · #20 11-24-2015, 04:56 AM

pretty sure there is no ABS on this 85 300TD. The pulsing wasn't there before rotor, caliper and pad change so it should be something with these items. Going to try new pads again with the new rotors in case the other pads have an uneven wear to them from the previous warped rotors.

Stretch · #21 11-24-2015, 06:26 AM

Quote:

Originally Posted by Jareb

pretty sure there is no ABS on this 85 300TD. The pulsing wasn't there before rotor, caliper and pad change so it should be something with these items. Going to try new pads again with the new rotors in case the other pads have an uneven wear to them from the previous warped rotors.

If you have got ABS it will look like this under the bonnet =>

Image from this thread => ABS on a w123 300TD?

If that pump isn't there then you don't have ABS

In which case I'd remove the front wheel and measure the run out of the disc with a DTI (also called clock gauge).

Here in Holland at this time of the year you can get free brake / winter health checks - so if the weather is miserable see if someone will measure it for you.

If there's nothing wrong with the discs - check your wheel bearings (people who do the tighten and then slack off 1/4 turn trick often don't realise this might not be good for a Mercedes - wheel bearing clearance is pretty small on a W123 compared with other lesser forms of automotive life form)

Stretch · #22 11-24-2015, 06:27 AM

Oh you're in Florida - forget about free winter health checks. Probably be a bit of a drive for you to find someone who will do that!

Jareb · #23 11-24-2015, 06:40 PM

Definitely don't have ABS. The tech that did the work does adjust the wheel bearings by "feel". He says he's done many this way and he has an excellent reputation but I guess this could be the problem. I would assume that if the pulsing is due to wheel bearing adjustment then the bearings are adjusted too loose?? Or too tight??

Stretch · #24 11-24-2015, 09:41 PM

If the clearance isn't right then I would guess it is more likely to be too loose. But in either case a DTI will give you a much better idea what's going on. Measure!

leathermang · #25 11-24-2015, 10:15 PM

The FSM calls for using a micrometer.....
not setting it by feel... no matter how good the mechanic thinks he is....

vstech · #26 11-25-2015, 01:22 AM

Quote:

Originally Posted by leathermang

The FSM calls for using a micrometer.....
not setting it by feel... no matter how good the mechanic thinks he is....

How would you use a micrometer to set bearing play?

mannys9130 · #27 11-25-2015, 01:40 AM

He means dial indicator, and he's right along with Stretch.

I don't think anyone could set the spec by feel. You could get close, but still. Precision requires an instrument.

leathermang · #28 11-25-2015, 08:36 AM

Yes, I was using generic ' able to measure small distances'.... but there IS something called an ' outside' micrometer.... a dial indicator is an outside micrometer with a dial for viewing... the easiest thing to use for sure... when working at a front end shop we had dial indicators which would hold the maximum distance that was moved.. so you could put it on a ball joint or such... get your pry bar to move the suspension, retrieve it and see what movement occurred.... so you would not need to be looking at the instrument at the time the movement occurred....you can buy thermometers which will hold the highest or lowest temperature reached.

http://www.amazon.com/b?node=4989301011Outside Micrometers & Accessories

""Outside micrometers and accessories are used in fields such as engineering, machining, and metalworking for precise measurements of an object's outside dimensions. An outside micrometer, also known as an external micrometer, has a calibrated screw mechanism for consistent measurements that can be as accurate as 0.0001" or less. It may display readings in inch or metric units on a vernier scale, dial indicator, digit counter, digital readout, or a combination of these. While many outside micrometers have a flat-faced anvil and spindle for general-purpose use, some have measuring faces designed for round workpieces, narrow shafts, grooves, hubs, or other non-standard surfaces. An outside micrometer set may be selected to cover a wide range of measurements. Interchangeable micrometer tips may be used with certain instruments. Various accessories such as a stand, case, ball attachment, and battery are available for use with an outside micrometer. ""
""

Jareb · #29 11-29-2015, 02:51 PM

I 'll try to find a shop nearby that can set the bearings with a dial indicator although I don't know of any.
I just cant believe that the hubs are bad since they were fine before the brake job. Its gotta be the bearing adjustment or pads that had worn in to the warped rotors....nothing else makes sense to me

leathermang · #30 11-29-2015, 03:23 PM

I can not visualize improper wheel bearing settings causing ' pulsing'...
I can visualize some rotor situations causing it... but not now that you have replaced the rotors more than once.... I sure hope you or someone figures this out... I hate unsolved mechanical problems...