Early Front Calipers for R107

[Pawel66]

I am helping a fellow Club Member here.
He is looking for early front calipers for R107. He was told that on early cars, such as his, the brake discs were narrower than the later ones as they were not ventilated. Therefore the front calipers had also narrower space between the pistons that could accommodate those narrower discs.

Is it true? He is having trouble finding such calipers.

What I seem to have found on SLS pages is information about early discs having smaller diameter, 273mm vs. later ones of 278mm - and there are corresponding early calipers for those discs. Nothing about the width of the disc/caliper and nothing about the discs being of ventilated or non-ventilated type.

Can you help determine if he is looking for the right stuff?

 

[Leester]

Hi Pawel,

This might help but no guarantees. Pelican Parts shows front brake discs only as ventilated 273 X 22. I searched using 1972 350SL. See here and scroll down:
https://www.pelicanparts.com/catalog/SuperCat/16296/MBZ_16296_BRKDSC_pg1.htm

As for calipers:  https://www.pelicanparts.com/catalog/SuperCat/16296/MBZ_16296_BRKCAL_pg1.htm.

Maybe a further search using the MB part number might provide more information on the calipers.

good luck,  Lee

[MikeSimon]

The R107 350SL came out in March of 1971 in Europe as a 1971 model. Pelican Parts is probably U.S. version oriented. It is quite possible that MB made a change rather early in the run.

[Pawel66]

Hi Pawel,

This might help but no guarantees. Pelican Parts shows front brake discs only as ventilated 273 X 22. I searched using 1972 350SL. See here and scroll down:
https://www.pelicanparts.com/catalog/SuperCat/16296/MBZ_16296_BRKDSC_pg1.htm

As for calipers:  https://www.pelicanparts.com/catalog/SuperCat/16296/MBZ_16296_BRKCAL_pg1.htm.

Maybe a further search using the MB part number might provide more information on the calipers.

good luck,  Lee

Leester, thank you for your help!

Yes, I am aware there was a change 12/72 as per SLS and now as per Pelican parts. The pre-12/72 calipers are available there. I certainly searched the parts list in EPC and there is a change as of certain chassis number, but it does not state neither disc ventilation nor diameter. In fact it recommends just replacement of the early calipers with late calipers (which makes sense, but my colleague does not want to do it due to originality - he has his car with 30k documented miles, etc.).

The question remains about the nature of this change - width of disc, diameter of disc or both?

[Pawel66]

The R107 350SL came out in March of 1971 in Europe as a 1971 model. Pelican Parts is probably U.S. version oriented. It is quite possible that MB made a change rather early in the run.

Thank you Mike! I followed your idea and yes - there are two changes of parts numbers there:

For 107023 at chassis 000237 and then at chassis 005716
For 107043 at chassis 00640 and then at chassis 009600

But I cannot tell what these changes were.

After yours and Leester's inputs (thank you!) I have a couple of questions to come back to my colleague.

[WRe]

Hi,
the early R107 had two different front brakes. The changes must occur very early because table book from 1972 mentioned two different types ("1. Ausf./2. Ausf.") already, see att. files.
...WRe

[WRe]

Hi,
if you look into the ATE classic catalogue you can find your numbers and dates.
...WRe

[Pawel66]

WRe, thank you so much!

I will study the documents from your first post - this should provide info on the discs.

Thank you for reminding of the ATE catalogue, I completely forgot about this source!!!

The difference I see in your documents for the calipers:
Bremsklotz breite (brake pads width).
Schachtbreite - this one I am not sure what it is...

The differences in discs (other than tolerances):
Durchmesser (diameter).

No difference in Bremscheibendicke (thickness).

I think I am now able to determine which type he needs when I get a VIN from him.

[Pawel66]

Interesting...

I do not see the early discs in the ATE catalogue...

[WRe]

... maybe this?

[Pawel66]

Thank you!

It is a very clear list. I do not think I see discs there though...

I am waiting for the VIN, I want to make sure we understood correctly which 107 we were talking about.

[Pawel66]

Thank you, everyone, for your kind help!

I gave the part numbers to my colleague and, actually, sources too. it looks like this story about narrow non-ventilated disc was not exactly true, at least I could not verify it. I suppose, like many of such stories, it boils down to someone replacing calipers for cheaper ones - but this starts being my story...

[stickandrudderman]

As I understand it the different versions are for vented and non-vented discs, with or without brake pad wear sensors and early or late (thick or thin) brake pads.
The change in pad thickness was related to a change in service intervals from every 5000m to every 6000m
The key differences are the width of the aperture where the pads fit and whether or not there is a cast lug at the aperture on which the brake pad wear sensor apparatus is mounted.
There's also a difference in the way the brake pipe is connected: At right angle or at about 45 degrees.
Here's a couple of photos of a new one I have in stock and even I don't know exactly which car it fits!

[Pawel66]

Thank you for this information!

I checked my fellow Member's VIN, date of manufacturing, found the MB part #, found ATE part #, verified with the ATE catalogue and technical specs provided below.

His car was equipped with calipers for 22mm ventilated rotor. He was told his car (450SL, not 350SL) was an early one, where Mercedes fitted the calipers with non-ventilated rotors, etc. But it looks like his car was not an early one, it had regular calipers for 22mm rotors as per specs. So it looked to me more like one of the POs, facing stuck calipers, replaced them with different (cheaper?) ones they had at hand (fitted in other Mercedes cars). Then sold my colleague on that story there.

[MikeSimon]

Pawel: As was mentioned before, I think< if his car is a 450SL, it couldn't be an "early" model. The early R107s in Europe (MY1971) were 3.5L 350SLs. The 450SL 4.5L came out for MY1973

[stickandrudderman]

I don't think the calipers are different for 350/450.
Pawel, see if you can compare with mine so at least I can identify what I have please.

[Pawel66]

Pawel: As was mentioned before, I think< if his car is a 450SL, it couldn't be an "early" model. The early R107s in Europe (MY1971) were 3.5L 350SLs. The 450SL 4.5L came out for MY1973

Exactly. His car is 1974, VIN around 20k... of 450SL. This is what happens when you move from talking to hard data.

Thank you for your kind interest!

[Pawel66]

I don't think the calipers are different for 350/450.
Pawel, see if you can compare with mine so at least I can identify what I have please.

Stick, I did not get to the place where I would have exact pictures of particular type of calipers. As a source of the new ones I recommended to him either Mercedes dealer or SLS. There are a lot of pictures in SLS, but I have no idea if they visualize true actual type of caliper.

However, if you look at what WRe provided, there are quite detailed descriptions of e.g. pads and rotors dimensions, maybe this would be helpful.