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914World.com _ 914World Garage _ Front caliper options
Posted by: Hammy Feb 8 2005, 05:01 PM
Well my mechanic says something about the front calipers aren't releasing the brakes all the way. What could this mean? I've been reading about the BMW 320i caliper replacement. If I were to buy the BMW calipers, could I have a local brake shop put them on (we know nothing about this stuff)? Or is it too complicated? 
Posted by: brant Feb 8 2005, 05:13 PM
Its not too complicated, but cheaper and just as good to rebuild yours.
have your shop rebuild the stock calipers...
or buy rebuilt ones from a FLAPS and then trade in your old ones as cores.
Posted by: skline Feb 8 2005, 05:15 PM
Sounds like you got some sticky calipers. I am going to use the Volvo calipers on my white car like I did on the Chalon. They are $150.00 for the set fully rebuilt from the parts store. Use a 1/8" spacer and you are good to go. I would of course remove the rear proportioning valve and run a larger M/C but I am not 100% sure if that is needed. I have not changed out the one on the Chalon yet and it seems to stop just fine.
Posted by: Hammy Feb 8 2005, 05:25 PM
Well won't the BMW calipers give better stopping power? I figured since the front calipers need a rebuild, I'd just have them exchanged out instead.
Posted by: brant Feb 8 2005, 05:33 PM
Zack,
its a highly debated topic around here.
but most of the bmw brake conversions Do Not use vented rotors...
so they don't increase the thermal mass and can overload the stock rotor.
My opinion is that a good stock caliper (rebuilt) with good pads and fluid will be very adequate and maybe just as good as a bmw caliper.
(plus cheaper and easier)
b
Posted by: Hammy Feb 8 2005, 07:29 PM
Ya thanks. It's in the shop now and I'm going to have them rebuilt.
Posted by: jim_hoyland Feb 8 2005, 09:01 PM
Volvo Calipers ? What models brakes are a direct fit ? I've got a volvo and have always liked the braking....Hmmmmmm
Posted by: Aaron Cox Feb 8 2005, 09:03 PM
| QUOTE (jim_hoyland @ Feb 8 2005, 08:01 PM) |
| Volvo Calipers ? What models brakes are a direct fit ? I've got a volvo and have always liked the braking....Hmmmmmm |
240's had non vemted and vented 4 pot calipers
Posted by: SpecialK Feb 8 2005, 09:06 PM
I've got a '74 with stock front calipers and MC, and a '73 with BMW 320i calipers and a 19mm MC, but since neither run at this time I'll withhold judgement until they do......Then we'll end this "this set-up" "that set-up" BS for good......(at least in my mind) 
Posted by: jim_hoyland Feb 8 2005, 09:06 PM
and correct spacing ?
Posted by: scott thacher Feb 8 2005, 10:18 PM
well i currently have the 320 i brakes on mine
and to argue the " over heat/load the front brakes" thing it takes x amount of friction to stop, so weither the pads are stock or bigger does not matter. same amount of heat either way, it does not take more friction to stop a car with bigger pads just less hydrolic pressure. but for general street use either way, but for track i would go vented.
Posted by: 914GT Feb 8 2005, 10:23 PM
The 320i brakes are working great on my car.
Posted by: skline Feb 8 2005, 10:24 PM
Ok, in all fairness, I am running vented front rotors on the Chalon. However, Bernbomb is not running vented rotors and he is running the 240DL calipers on his car. He likes them and has not had any problems with them as far as I know. He has had them on there for more than a year now. I hope he chimes in here and says something. The pads are nearly twice the size of even the BMW pads.
Posted by: Aaron Cox Feb 8 2005, 10:45 PM
i got a set of volvo 240 calipers to throw on my car ..... will it clear the wheels..... 
also... do they sit all the way on the rotor?
Posted by: Brett W Feb 8 2005, 11:50 PM
Alright here is the skinny onf the Volvo Calipers:
Come from a 190 and 240 early 80s to early 90s
There are two kinds. Vented and non Vented.
The calipers I have are Girling, have not inspected the ATEs.
They have a 3in bolt pattern on the calipers.
The non vented calipers sit .050 off the centerline of the tock rotor, towards the wheel. You will have to shim them back a little.
The vented calipers will work with a .810 rotor.
Both calipers are the same as far as major dimensions . The vented caliper is not machined as much so it is thicker.
All volvo calipers are dual circuit. They will require an adapter block or a set of custom bent hardlines to be fed from a standard master.
The calipers will overhang the edge of the pads. They will work perfectly with an 11.75 aftermarket rotor. You can either machine the pads or take just deal with the over hang.
I have an aftermarket aluminum hat and vented cast iron 11.75 x .810 rotor that will work perfectly with the Vented caliper on the stock 914-4 cylinder strut (haven't test the early struts). To make it fit, the hub centric ring will have to be machined from the hub or open the hat up to clear the ring. (did want to mess up my prototype). The hat will slip over the existing hub giving you a 1/4 wheel spacer. Don't know if Fuchs will clear the fender wells, yet. I am still in the prcoess of developing this one for my top secret project but will be testing in a street car soon. I figure it will need a 23mm master cylinder. Might be able to use the stock 914 front calipers on the back or even run the Volvo calipers on the back. Haven't gotten that far yet. I haven't tested wheel fit as my steel wheels have all kinds of room for calipers. Don't know about alloys yet. There is plenty of material to clearence the caliper though.
Questions?
Posted by: GBallantine Feb 9 2005, 08:45 AM
For those who have done the 320 caliper conversion with a 19mm master and a brake bias control. Is there any difference in the pedal effort or feel? ( softer or the same)
GB
Posted by: Eric_Shea Feb 9 2005, 09:37 AM
w/Brant.
I'm not panning brake conversions. I simply like to look at them as a "whole" meaning front and rear. The BMW conversions I've heard mentioned on this board all seem to have positive results. My concerns would be brake bias in an emergency situation.
Let's face it gang... they may not have blessed us with massive horsepower but Porsche is one of the best, if not the best production oriented company on the planet at "brakes". A well sorted "stock" brake system will still stop your car faster than most cars behind manufactured "today". Rebuilt calipers with some of today's pad technoligies can make your car scream to a halt. This is a "very" well balance system. Including the proportioning valve we all love to hate.
If you're adding more "power" then by all means add more brake. You can look to Porsche for answers there as well. I added an early 911RS/930 system to my car because the intended engine rebuild would be in the same hp range.
To the original question:
1. Pistons can stick. The top of the pistons can get a bit crusty, especially if the boots are torn etc. The rubber seal can bind if the car's been sitting for a while. Make sure they hone your cylinders and polish your pistons during the rebuild process. (I think there's a Beavis & Butthead joke somewhere in that last sentance... 
)
2. The factory rubber lines can deteriorate and swell internally allowing fluid to pass through under the extreme pressure of pedal application yet will not easily allow the fluid and pressure to release the pad... hence sticking.
Don't have your calipers rebuilt without investing another $12.00 per side in new factory rubber lines. Good luck.
Posted by: Lawrence Feb 9 2005, 12:34 PM
Stock calipers work well. You can rebuild them yourself in a little while, or have your mechanic do it. The kits are readily available. Otherwise, your local auto parts store should have rebuilt calipers available.
When was the last time your rubber brake lines were replaced? They swell internally with age. When you stomp on the brake, fluid is pressed through and the brakes lock. When you release, there's no corresponding pressure to force the fluid back out of the caliper - the caliper stays "stuck".
Change the rubber lines (if they're suspect) and flush the system.
-Rusty 
Posted by: type47fan Feb 11 2005, 09:20 PM
How about these?
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Posted by: bernbomb914 Feb 11 2005, 10:19 PM
I have had good luck with the Volvo calipers. I have solid rotors (stock) a 19mm M/C and no porp. valve. They fit the riveria wheels with a little sanding on the belt sander and fit the ATS wheels also. they stop much better than the stock brakes but I am not racing and use the car as a daily driver.
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Posted by: bernbomb914 Feb 11 2005, 10:20 PM
xx
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Posted by: bernbomb914 Feb 11 2005, 10:21 PM
last
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Posted by: Mueller Feb 12 2005, 01:07 AM
| QUOTE (type47fan @ Feb 11 2005, 08:20 PM) |
| How about these? |
those look familiar
(911 vented rotor)
Posted by: dmenche914 Feb 12 2005, 01:55 AM
want to turn stock 914 front brakes into supper brakes?
Purchase Porterfield brand pads. High Performance House sells them. They are pricey pads, but I have experienced no better braking than with them on my stock system 9except for teflon /stainless braided hoses. Even my master is stock.
Go with the Porterfields, you will not be disapointed. It was like night and day between them, and the regular pads.
Porterfield man, Porterfield
No conection to Porterfield Company, just a heck of a satisfied user.
Posted by: Hammy Feb 12 2005, 01:59 AM
Are the rubber lines sold with the rebuild kits?
Thanks dmenche, i'll look em up.
Posted by: 914efi Feb 12 2005, 08:36 AM
My experience with carbon pads (performance friction) which I assume is what the porterfields are is that they are awesome, but only when HOT. At normal temps they are no different than std pads. Correct me if I am wrong about the porterfields.
I have mazda RX-7 4 piston calipers on my -6 and they help. Still have the std rears and prop valve and the std m/c. If I recall, they have about 12% more piston area than the M calipers. Obviously, the mazdas are not a bolt-on. Strut mods are required.
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Posted by: skline Feb 12 2005, 09:15 AM
Hey Bernie, where did you get this block at? I had to use the same junction I used to replace the rear proportioning valve. This looks much cleaner. Where did you get it?
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Posted by: john rogers Feb 12 2005, 01:39 PM
I just put the Volvo calipers on the front of the race car as Bernie did and they seem good. Tere is a little more pedal travel but not bad. I had BMW front and back and had some trouble with brake fade at a couple of races in Mexico since there was not as much heat disapation as I needed. I also used a 36 section of brake like on each side of the front with some loops so I have a much larger fluid volume up there which was recommended by several BMW 2002 vintage racers as that is what they did. I have had the 23mm m/c for about 2 years and it works well. I plan to go to the 4lug adapter kit shortly I hope and will do some picts when finished.
For the adapter block check out the Datsun 311 roadster board as they have a good article on installing the Volvo calipers and I got my blocks from their source. Here's the address: http://www.311s.org/
Posted by: bernbomb914 Feb 12 2005, 02:39 PM
scott the tees came from Rich Johnson (a914guy@aol.com) they allow you to use your origional brake lines. cost as I remember was 45.00 for the pair
Bernie
Posted by: skline Feb 12 2005, 03:37 PM
| QUOTE (bernbomb914 @ Feb 12 2005, 12:39 PM) |
| scott the tees came from Rich Johnson (a914guy@aol.com) they allow you to use your origional brake lines. cost as I remember was 45.00 for the pair Bernie |
Cool, thanks Bernie, I will have to get me a set and upgrade the Chalon. I used seperate lines and a T like in the back. Looks like a spider or something down there. I like the block much better. Its cleaner. Besides, I may put them on the 74 also. A fast car is only as good as its brakes.
Posted by: 914efi Feb 13 2005, 10:56 AM
I got a few PMs about the mazda calipers, so I will add a few photos here of the strut and jig for modding the strut. It's a little hard to see, but you can see the upper mount weld bead in one of the pictures. I did this about 5 years ago, so there may be better options out there now.
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Posted by: 914efi Feb 13 2005, 10:58 AM
another
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Posted by: Dad Roberts Feb 13 2005, 07:10 PM
I've been following this topic and lookin at some of the other s about 914 brakes. I'm curious because I'm runnin the 914 rear caliper on my Type III. The front caliper on mine is the same, but no E-brake setup, of course. My master cylinder is also 19 mm. Does anyone know the stroke of the 914 19 mm cylinder? My VW one is 15 mm. My rear brakes don't seem to work as well as they should. I'm tyryin to figure them out. I have a clue now that I know the MC is the same size that they are probaby frozen. Any help would be appreciated..........Dad 
Posted by: Howard R Feb 13 2005, 08:32 PM
I'm running the Volvo calipers on the rear of mine. I got around the need for the external pipe work by drilling through from the bottom piston bore to the top one, and then put bleeder nipples in the redundant holes.
Posted by: Aaron Cox Feb 13 2005, 08:41 PM
how can we make the volvo calipers sit further "in" on the rotors to utilize the whole pad?
Posted by: Brett W Feb 13 2005, 08:45 PM
Why bother just get a bigger rotor.
Posted by: Aaron Cox Feb 13 2005, 08:49 PM
| QUOTE (Brett W @ Feb 13 2005, 07:45 PM) |
| Why bother just get a bigger rotor. |
that works too.
i have 70-73 911 rotors. what rotor would i need? SC? Carerra? 930?
Posted by: Brett W Feb 13 2005, 10:30 PM
Any rotor that is 11 3/4" Diameter.
Posted by: Travis Neff Feb 14 2005, 11:25 AM
For solid rotor conversions, you can get brand new calipers for $69 each.
http://www.fcpgroton.com/volvo240brake.htm#calipers
Posted by: Aaron Cox Feb 14 2005, 02:46 PM
vented is even cheaper....
http://replacement.autopartswarehouse.com/parts/autopartswarehouse/wizard.jsp?year=1986&make=VO&model=240--004&category=N&part=Brake+Caliper
59 bucks.... a side + core
Posted by: Travis Neff Feb 14 2005, 02:55 PM
No core charge on new units, but the calipers for vented rotors is cheeap just the same!
Posted by: brant Feb 14 2005, 04:07 PM
| QUOTE (914efi @ Feb 12 2005, 07:36 AM) |
| My experience with carbon pads (performance friction) which I assume is what the porterfields are is that they are awesome, but only when HOT. At normal temps they are no different than std pads. Correct me if I am wrong about the porterfields. |
Performance friction versus portefield:
every different brand has different compounds.
In fact many brands offer different compounds within their own brand.
Portefield makes a street and a track version.
the street version works much better cold.
I use cool carbon on my race car and have tried 3 different compounds from them.
lots of difference in the compounds.
I think pads and fluid can make stock brakes into awesome brakes!
Posted by: Brent Feb 14 2005, 04:30 PM
What is the preferred Porsche option for vented rotors? 911, SC, 944, or other? I believe I have 80's SC, but spec to verify. Is there a tech page with specs avail?
Posted by: Two914s Jun 13 2005, 01:40 PM
It is a little hard to see in the pictures....but are the Volvo 240 calipers aluminum or cast iron? I wonder what they weigh compared to a stock 914 caliper, a Porsche M caliper, or BMW caliper.
What if I wanted to use a Porsche 911 strut with the 3 inch bolt spacing (for M calipers) but with the Volvo calipers intead of the M? Will the calipers fit over the vented Porsche rotors? What model car has the ones that will fit. The parts counter guys always want make, model, year, etc.
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