Volvo Front Caliper Conversion
First off, let me say that any thing you decide to do to your braking system is done with no liability to 311s.org. This is a template and not a bible for doing the conversion. Your experience is entirely in your own hands. Brakes are a serious matter and if you do not feel comfortable working on them, take your car to a reputable brake shop. With that said, roadster parts are expensive and it is not going to get cheaper any time soon. I was looking for an alternative that would be as close to a direct bolt-up as I could find. I was not the one who discovered this conversion as others had already done it but there was no written documentation or parts list. I have no idea who originated the idea. Several of the vendors sell similar packages. I am just trying to document the conversion and make it easy for the mechanically inclined roadster owner to complete the conversion with minimal expenditure and fuss.
This conversion is not for everyone. There are those that cringe at the thought of non-stock parts in a roadster. I am not one of those die hards and anything goes for me and my cars. Heck, I am running a 2 liter forklift motor in my 67.5. No doubt the stock braking system works very well when maintained properly but one piston costs as much as one Volvo caliper.(At least here in California.) The calipers that will work are from a 1975 240 Volvo. They are Girling style, 4 piston for the non-vented rotor. They come in LEFT and RIGHT hand. They are available loaded(with pads) for around $50.00 each plus a core fee. Buy loaded calipers to save yourself a lot of headaches if you can. Another alternative is the U-Pull-It junk yards. There appears to be calipers out there that are not OEM spec and have poor castings around where the brake lines fit that make it impossible to get a good seal using the brake manifold adapter. If you are going to use the brake manifold method designed by Mark Sedlack you must have the OEM calipers as they are machined flat where the manifold bolts to the caliper.
Here are some of the pros and the cons. First, you are going from a 2 piston caliper to a four piston. The surface area of the brake pads is larger with the Volvo calipers. Plan your project and get all the parts needed before you tear your car down. Roadster caliper pistons run around $60.00 to $70.00 each times four. The roadster caliper rebuild kits generally do not work on worn out, rusted pistons. Getting stock calipers re-sleeved is expensive and will cost you as much as the conversion if not more. Getting the rotors cut is generally inexpensive-$10.00 to $15.00 each. The source for the brake manifold designed by Mark Sedlack which utilizes either the single stock brake line or a single SS line is Breck Meyer. He is offering them for $60/set with free priority mail shipping(3 day) included. His email address is email@example.com
The calipers should be available from any Auto Parts store. Replacement pads are readily available and cheap as well. The Volvo calipers have two inlets as seen by the following picture. Take notice of the green colored caps. I used A1 Cardone part # 17630(right) and part # 17631(left)
There are several ways to plumb the brake lines. The old way is with a tee and two steel lines. For this you need two brass tees Earls Performance PN 972050 with two 3/8ths x 24 UNF inverted flare fittings on the sides and one 3/8ths x 24 UNF straight fitting branch for the rubber brake line to connect to. It also has a 1/4 hole for mounting. The web site where the tee can be purchased is listed below the parts list. Just buy some steel brake line with the fittings already attached. Get two 12" 3/16ths lines with the 3/8 x 24 connectors and buy two 6" 3/16ths brake lines with the metric 10mm x 1 connectors. That way you only have to do two double flares and two bubble flares. NOTE: Lou Smaldino did the conversion on his roadster. He ended up buying 4 metric tubes, with two Standard tubes and just concentrated on cutting the metric tubes and making the regular flares on them which was much easier.
We need to make up two 5" and two 11-1/2" long lines with a double flare 3/8 x 24 connector on one end and a bubble flare 10mm x 1 connector on the other end. They will need to be bent to connect properly to the tee and the caliper. I suggest mounting the caliper and tee loosely and then bending from one connection to the other-slowly. Here is a template so you can get your bends within the ballpark to begin with. Brake Line Bends.PDF
NOTE: The conversion between photo copying, scanning and converting to PDF changed the scale a bit but it is better than starting from scratch.
The second and better way to plumb the brake line to the caliper is to use the manifold designed by Mark Sedlack that bolts to the caliper requiring only a single brake line connection. A quick explanation-Mark designed a manifold bracket that eliminates the brass tee and tightly bent brake lines altogether. The manifold bolts directly to the caliper with 1" banjo bolts and crush washers on the top and bottom of the manifold. There have been some reports that the castings on the Volvo calipers was uneven enough that a good seal could not be obtained. Mark Sedlack did not have that problem nor did I. You can read Mark's write-up here!
You are on your own getting the adapter made as the fellow who used to make them has quit. Sorry but stuff happens.
To use the first method you will need a to purchase a good brake tubing double flare kit. You get what you pay for so spend some money the first time around. You will have to form at a minimum two bubble flares to connect to the Volvo calipers and two double flares to connect to the brass tees. A good tubing bender might come in handy as well. Purchase 4 new grade 8 bolts 1/2-20 x 1-1/2" and lock washers to mount the calipers along with 4 to 8 flat washers for shims to center the calipers on the roadster rotors.
You will need to have a minimum of 1/8" machined from the diameter of the roadster rotor to provide clearance for the new calipers. Several people have reported this was not enough. Taking more off of the diameter of the rotor will hurt nothing. You do not want the rotor scraping against the caliper. Some people have ground the clearance out of the caliper. I prefer having the rotor turned down. Stock rotors are 11.18 inches in diameter. So for all practical purposes you want rotor diameters between 11.0500 and 11.1175". This equals a little under a 11-1/8" diameter. You should be able to go retro with the turned down rotors as we are talking diameter not thickness. Cost of this will vary depending upon your location. Again, this is required to provide adequate clearance with the Volvo caliper. Next you must redrill the mounting holes on the Volvo calipers to 1/2" so the roadster mounting bolts will fit. Reinstall the rotor and bolt the new caliper on using a washer or two as a shim and the new grade 8 1/2 -20 x 1-1/2" bolts we purchased earlier. Remember the calipers are left hand and right hand. Get the right one on each side otherwise you will have problems bleeding the brakes. NOTE:The extra bleeder valve goes to the top! Ask Lou, he knows all about that one. Next we need to plumb the brake lines. Install the new brass tee loosely. Install both new brake lines we fabricated earlier. I started at the caliper and got the threads started real good. Then you can tweak on the line to get it lined up with the tee connection. Do not try to force it as cross threading will really ruin your project. There is only one way to route the lines and it will become fairly obvious once you install the caliper and brass tee. Here is a picture of the plumbing and hardware.
Here is a picture compliments of Eric Smeby of the plumbing and hardware mounted.
If you are more of a visual person--you can view more pictures of the actual plumbing fittings and plumbing by clicking here!
Also, there is an interesting article on the different types of brake line connections. Pretty good reading and very informative even though it was written for British Ford racing enthusiasts. You can read it by clicking here!
This conversion is best suited to the dual master cylinder cars 67-1/2 and later. The roadster master cylinders are standard thread. If you plan on doing it to an earlier car you might want to upgrade the single brake master cylinder to a 1975-77 280Z 7/8" cylinder. OEM master cylinders for the Z car are 10mm metric. There was no cut-off from metric to standard. They are all metric. The tubing for the brake lines is a standard 3/16. It is the fittings that are different. A standard thread will go into the metric fitting but it strips the metric threads and does not guarantee a leak proof system. Rebuilt master cylinders can sometimes be re-tapped to standard threads because someone has already stripped out the metric threads. If this has been done the rebuilt master cylinder comes with the correct fittings to be placed on the brake lines. There is a 30 to 45% failure rate on rebuilt parts-not just master cylinders. So it is possible that the rebuilt master cylinder some of you have installed had been re-tapped to standard threads. They do not come from the factory that way. To assume that all re-built units have been re-tapped is a disaster waiting to happen.
Another note from Lou: "I picked up the 76 280Z master cylinder at the local shop for 79 bucks installed the plunger from my original Master and also had to put the front tank from the stock master on the new master so my hood would close." Several converts have reported that the early style 13/16" rear wheel cylinder is well suited to the 280Z master cylinder. Bias does not appear at this time to be drastically affected. We are talking street car here not full out racing. There may be clearance problems with the stock air cleaner but this is no problem with any of the engine swaps i.e. SR20DE, VG30, or the 240SX.
Once all your connections are made and tight it is time to bleed the brakes. You can read about that by clicking here!
Below is a shopping list for the above conversion:
- 1975 Volvo 240 RH caliper, girling, non-vented A1 Cardone PN 17-630 Price around $45.00 + core
- 1975 Volvo 240 LH caliper, girling, non-vented A1 Cardone PN 17-631 Price around $45.00 + core
- 4 each 1/2" -20 x 1-1/2" bolts with lock washers and extra flat washers for shims
- 8 each 1/2" flat washers for shims
- 1 each 1975-77 280Z 7/8" brake master cylinder(Victoria British) PN 64-101 Price $79.00 -$100.00 **Not necessary for 67.5 and later
Method #1 for plumbing:
- 2 each brass brake tee adapter 3/8" x 24 UNF PN 972050 Price $12.00**
- 2 each 3/16" stainless steel brake lines with 3/8 x 24 UNF connectors 12" length $5.00
- 2 each 3/16" stainless steel brake lines with 10mm x 1 connectors 6" length $3.00
- 2 each 1/4" x 1" bolts with lock washers and nuts to mount new tee $1.00. The price recently doubled on these. The brass tee adapter, banjo bolts, and crush washers are available from American Street Rod - click here to order!
Method #2 for plumbing:
- 2 each custom fabricated manifold-$60.00 including shipping-from Breck Meyer
- 4 each Earl's 10mmx1.0 single banjo bolts part#EAR-997517 (Summit Racing)
- 1 bag crush washers 10mm part# EAR-177100 (Copper works better than aluminum-Summit Racing)
Installing SS lines instead of the stock rubber lines(Pegasus Racing):
- 2 each 3AN to female 42 degree inverted flare 3/8x24 part# 3265-12
- 2 each 3AN to 3/8x24 large hex for crush washer part# 3265-26
- 2 each 14" -3 straight to -3 straight stainless brake line part# 3-14-s-s
So as you can see, this is not a hard project if you are mechanically inclined. If not just spend the dough on the stock caliper pistons or better yet take your car in and have the brakes done by a professional. Of course your experience may vary. I will remind you one more time though. Brakes is serious business and 311s.org accepts no responsibility in your decision to use this write up to do the conversion. You are accepting sole responsibility for your own actions. Good luck, be safe and happy roadstering.