940 Brake Upgrade With 302mm Discs.

[Steve940estate]

Now that I have fitted the larger brakes onto my car and it’s all working I thought it would be useful to list all the separate parts and give details of those that were modified.

The standard front discs fitted to later 940’s with Girling calipers are 280mm and by using parts from later models you can fit 302mm discs, matching ATE calipers and have a better range of brake pads to choose from.

These parts were fitted to some Phase 1 V70’s, C70’s, and are often used to upgrade 850’s, the only disadvantage is that you need 16” wheels or larger to clear the brake calipers. Some have found that certain genuine 16” Volvo alloys can hit the calipers so you need to check the ones you plan on using clear OK.

While this a fairly straightforward job you will need to make some modifications to the brake caliper carriers, fit some spacer washers where they mount on the front struts and use longer mounting bolts.



Parts List.



Brake Discs.
For these you need 302mm diameter discs. I went for genuine Volvo ones part number 31262095.

Brake Caliper Carriers.

There are 2 Volvo part numbers for these. Until you see both the only obvious difference is the price !
When you open the boxes it’s obvious one is plated and the other has a paint finish. I am pretty sure the plated one is a brand new item and the cheaper painted one is refurbished.
Another thing to watch is that my painted one had difference in the casting despite having the same part and casting number. Others have thought in the past that this difference in the castings was why the price and part numbers are different but I don’t think that’s correct.
Volvo part numbers for these are,
8251319 for the cheaper painted version.
8602456 for the more expensive plated ones.

To fit the carriers you need to provide clearance for the ABS sensor ring on the back of the hub. It’s easier to show what is needed with a few pictures. After filing I painted the bare bits so it would look nice for 5 minutes at least.





Spacer Washers.
You will need a total of 4 spacer washers to allow for differences in the brake disc dimensions. I made mine from 25mm diameter steel bar with a thickness of 6.3mm. The thickness isn’t super critical so going slightly bigger, ¼ “ or 6.5mm would be OK. When you fit the carrier over the disc you will see the carriers are a bit rough being just castings.

Carrier Mounting Bolts.
Due to the spacer washers the carrier mounting bolts need to be slightly longer. I bought some new M12x 35mm socket cap bolts.

Brake Calipers.

Volvo calipers are over £100 each so I went for reconditioned exchange Delphi ones. If you ask for Volvo 850 ones it’s easy as they are all the same.
Delphi part number LC4657 and LC4658

Caliper Slider Pins.

These don’t come with the callipers unfortunately and the factors I asked don’t sell them. Volvo ones are quite expensive at around £10 each. You can get them for about £4 each from Big Red which is quite a lot better. I found that because they are a fairly standard part made for ATE brakes they are fitted to other cars. Probably the most common use of ATE brakes is on Vauxhalls and checking part numbers found a lot of Cavaliers used them. I ended up using good used ones as a friend had some spare so if you have time and want to save a few quid a hunt round a breakers might be worthwhile.
Volvo part number for these is 30648017
The ATE number is 11.8171-0008.1

Brake Hoses.
I re-used my original hoses along with the stainless steel extensions that fit between them and the callipers. If you feel the hoses look stretched you can use some slightly longer hoses, listed for Phase 1 V70’s with 16” wheels.
Here are the numbers for each.
3546813 335mm long and fitted as standard to 940’s.
9191400 355mm long.



Brake Pads.
I decided to try the police spec ones that are available for 850’s and V70’s. This is really down to personal preference. Anything made for the 850 will fit along with those from V70’s and C70’s as long as they use the same callipers.
Part number for the police spec ones are 30645240 and are supposed to not have sensor wires. Mine came with them so I carefully cut them off.

[Neoott]

Great post here mate very much like it. Looks like these are going to give you a niec amount of stopping power, might have to look into something like this for mine. Dont know if it will all fit a 700 too? (fingers crossed)
Also where did you get your nice wheel spacers? are they 20mm?
Dave

[Steve940estate]

I'm pretty sure everything fits the same. The only differences are that some earlier 700 series cars has discs with integral hubs. If the car isn't fitted with ABS the caliper carriers should bolt straight on. The brake master cylinder and servo might be different as well.

The brakes are better but I haven't finished yet. I am hoping that a change of brake servo and brake pedal to later spec versions will finish the job properly. Because the caliper pistons are very similar in size you only gain from the bigger disc diameter. The later servo will give a bit more bite hopefully.

The spacers are German made H&R ones, but were sent from the states !
After much searching it was easier to order them from IPD and they were still a bit cheaper then getting them elsewhere.

Thanks for the comments, took a while to find out all the right bits to get and if anyone wants to know anything specific just ask.

[Neoott]

Cheers, i do believe the master and servo are different. But in theroy i can replace all for the later version? Mine isn't ABS so that makes things easier. Im going to strip down my drivers side caliper at the weekend anyway as its started slightly binding so ill do some messuring If this doesnt work for mine, i have a set of Mitsubishi GTO calipers and discs in the shed (look very much like these http://www.ebay.co.uk/itm/2000-MITSU...item3f0e06e227) maybe i can make some carriers up for these
Dave

[Steve940estate]

There seems to be a few versions of everything, and then there are cars without ABS !
If your car has twin piston front calipers it might have two brake lines per side as well. You might need to do a bit of re-plumbing, fit a different master cylinder and a bias valve.
Some of the info on Turbobricks might be helpful as there are more people on there updating older cars.

[rogerthechorister]

Are the spacers principally because most of the 16 inch wheels are 43mm offset rather than 20 or 25?