I am trying to determine what fair market value for the following is…

* Pair of used rear 911 M-calipers. Is there a price difference for the early (with knock-back) and later (no knock-back and cup pistons)?

* Pair of used parking brake backing plates and associated hardware from a 70-73 911. I believe the 70-73 is the proper year range so that the mounting holes match the 914 trailing arm.

Condition? I am looking for working, but ready for rebuild/refresh. Basically what you might find if pulled from a running but tired 911.

As you can guess, I am looking to do an M caliper and 911 e-brake conversion on the rear of my car. I already have sourced A-calipers for the front.

You did not say if you are going with vented rotors? Early 911s had solid rotors through 69 on T models. Vented from 70-. I believe there is a thread about the vented rotors and rear calipers.

Vented rear. Basically the caliper/rotor combo used from 70-83 (aka the SC rotor/caliper). I am not 100% sure, but I think the 70-75 rear caliper had the knockback and the 76-83 did not.

Call Eric Shea and he will give you the figures you are looking for. He set me up with everything and I really don't think you can beat his price if you really tried.

I have some m calipers I got from 914sixer awhile back. I also have some 84 alfa romeo milano 48mm aluminum calipers that will bolt up in place of the m's. They have some kind of a black coating on them from brembo. The later models will be in the best shape probably. Everything is the same the alfa dosen't have knock back, it does use the larger pads than the m. The pistons are cup style and I'm pretty sure when I talked to zimms they said the a caliper cups will probably fit and they have some ss cups for a calipers for 33.50 each. It's not cheap to buy the rebuild parts so you can't spend a lot on the used calipers especially if they need pistons. I bought the steel armed 911 backing plates and about 84 944 angle pull adjuster assemblies, shoes and hardware all from the same wrecking yard including a 944 emergency brake cable and handle to put in the center. I also bought new vented rotors. I think if you know a local porsche wrecking yard you might beat the prices I paid but there are are no local porsche yards in Crawford or Waco, TX. I wrote up what I got and where I got it on other threads somewhere. Maybe also on the club site.

Erik has got the nicest rebuilt calipers and it will take a lot of work and expensive parts to match what he has.

I am going to probably do the 924/944 angle/side pull method on the parking brake. I am also a DIY kind of guy and will be rebuilding the calipers myself (even if it doesn't save me money). I probably will be taking to Eric to source the o-rings for when you split the calipers. I have a local guy who parts out 911s that I have bought from previously and will probably work with him first (as I am able to examine the part prior to paying him). But i need to get an idea on how much these are worth before I start talking money.

So if anyone can offer any help on typical prices I would really appreciate it it.

Got all my items off eBay;

- Early "rebuilt" M calipers (with knockbacks) - $60 shipped

- Pair of NEW rear vented rotors - $9.99 plus $20 shipping (that's right, $9.99)

- '83 SC parking brake assemblies complete - $200

The rotors were cheap because of the poor description they had. I took a small risk that paid off. Typically a pair of new vented rears are in the range of $100-150.

Then you need to decide how you want to convert. I can post pictures of mine which use crankarms or others have relocated the handbrake to the center. If you go that way, I've got a pair of used 911 parking brake cables I'll send ya for the cost of shipping.

If you go to the center a one to two cable off a 944 should work great. I got two different sets of 944 eb assemblies, all the hardware and shoes from two different yards I found on searching porsche yards. It was 160.00 for the early backing plates and a set of 944 shoe and hardware shipped to TX. from AZ. The other yard sold me the 944 cable, a nice leather covered handle and another set of 944 eb assembly. I posted the yards and prices on another thread here or on the club. The yards I used were familiar with this modification.

Being able to look at what the yard is selling is the best way to deal on these parts. I hate buying unseen parts because everyone says I am too particular. The backing plates are pitted some because of their age. The pistons are the question mark in used calipers. The ss pistons are the cats meyow but they cost enough to add significantly to the cost of the completed caliper. Also new pins and springs are expensive. I zink plated some of my hardware and that helped some but the pins that came with the second set of alfa calipers were pitted severly and even replating didn't help their looks.

Used alfa aluminum calipers were 250.00, those came with new pins and springs, without shipping from the northeast. I found a ebay alfa seller, They are called DiFatta Bros. Pretty nice seller. He new exactly what I was looking for. The second set were newer calipers but had shitty pins and springs. The second set had good pistons and the other had pitted pistons although the pits were outside the oring. I guess they will all have some pitting around the dust cover lip. Once the rust eats the chrome plating the damage is permanent and will only get worse. The black coating on the alfa caliper protects them well especially in the bores. Add 75.00 for ss pistons, 60.00 for pins and springs, 50.00 for rubber and it gets expensive real quick.

Thanks everyone for your help. I also talked to Eric via email and he helped as well. Between this thread and Eric's email I think I have a better idea on what it's going to cost.

Richard;

Here are my two cents;


It's not really possible to quote a fair price for most of this stuff. It's just old crap to some people and rare collecters items to others.

The condition of the items also varies a lot!! (I got my rear M calipers pretty much for free, and boy did that ever cost me!!!)

Then there is the problem that you are not buying a "complete" anything, but a collection of parts off of various cars.

What you have to do is just have a dollar amount in mind and then watch the net for stuff. Have money handy if something comes up.



I rebuilt my 911 rear M calipers and sourcing the correct parts can be difficult! I've gotten to know Dennis at Zim's real well. (don't talk to anybody else at Zim's!!! If he is on vacation for a month, just call back when he returns.)

You can get the o-rings from Pelican Parts, but you have to tell them the part number. If you don't tell them the number, they will tell you that they are not available and don't have them. Strange but true. The part number is; 901-351-928-10.

Buy the seal kit from Zim's and have all the dimensions for the pistons on hand. Both the diameter of the main piston area and also the diameter of the piston where the outer seal is in contact. (don't order them from Pelican) Don't assume that all four pistons (for both calipers) are the same!

Think about saving your self a lot of head-aches and just send them to Eric Shea.

I've seen the threads about using the "angle pull" e-brake set-up and think it's a good concept. However I don't think anybody has worked up a good solution to that 40mm spacer / backing plate that is required. That item not only is a spacer, it's also a backing plate for the spreaders!! (at least, nothing complete has been posted up that I've seen) If I hadn't already worked up my solution, I'd be working on that method.

Wes Vann

Wes,

Thanks for the info (particularly the part number for the o-rings). Regrading the angle pull, I haven't seen a complete setup with that, but I know a few people are trying to make it work. It looks like I will be one of them. But... if it doesn't work, there is plenty of other solutions using the 911 bowtie spreader that does work.

Since posting the questions above, I have talked to a local guy who parts out 911s and it sounds like he has a pair of the rear m-calipers for me. But he didn't have the parking brake assembly in the year range I am looking for. So I am officially looking for that now as well as a few other things.

Richard

One of the places I got the 944 shoes, hardware and angle spreaders with the early 911 backing plates was 20th st Auto Parts (602) 258-2020
www.20car.com

Also Brad says that the early boxter also uses the 914 bearing so the bearing retainer is the same and has the backing plate and also the angle spreader assy all in one but the picture seems to show the shoes are narrower, it could just be the picture.

I haven't started fabbing it yet but it seems like a piece of 3/16 or 1/4 wall x 1.25 or 1.5 angle cut down with a hole in the center for the spreader arm to protrude through thats 40mm wide welded on the bearing carrier would do the trick.
There is a picture of the boxter eb assy. on a thread that Brad has on the club. I have some 944 bananna arms that I can copy. The 40mm lug is part of the aluminum bearing housing.

Actually you can use the early 911 brake parts and cut little notches in the shoes and use the angle spreaders. The same spreaders also are used on bmw's.