9 inch disk brake conversion

[MaTTe]

Hey Rocket, have you gone any further with the volvo caliper conversion?
I've pulled a set of these 4 piston calipers off the 264 im pulling to bits, and i've been toying with the idea of fitting them up. I remembered a couple of days ago there was a thread on it somewhere, so i've been hanging to get back into the site to see what information is around.

I did a quick search around the other day trying to find as much info out about the calipers as possible, but finding the specifics was harder to find than expected.
I haven't done an accurate measurement yet, but the bolt spacing for the volvo caliper is smaller than the hq caliper, so i'll have to make up a bracket of some sort. The bit I was more concerned about is getting the depth right so the rotor is central within the caliper...
If i get a bit of time i'll look into taking some measurements...

The other thing is that apparently if you just put a T junction into the brake line to split the single line and join to the twin lines, it will increase the pedal travel which i dont think is really satisfactory. I'll have to look into the options there, whether it be drilling out the master cylinder, or adapting the volvo master cyl to suit.

Anyway, if you have any more info or ideas i'd love to hear what you think, it'd be great to bounce some ideas back and forth to improve the final outcome for us both

Cheers,
Matte

[Rocket]

Hi MaTTe, Because I run a 1" bore master cylinder my pedal barely moves now, so the brake specialist said my pedal will not move a great deal further with the Volvo 4 pots on the front. Making up another mounting plate will take a bit of work though. Also the the Volvo caliper requires that one machines the disc rotor down to about 23mm from 25mm. Which means one can use old HQ rotors instead of throwing them out.
Rocket

[MaTTe]

Hey mate, yeah i have a 1" bore on the master cyl too, the sites i was reading last week didn't specify what sized master cyl they were using, but from memory they said it'd near on double the travel as you're supplying both lines from a single line of the same size...
I did a bit of research on rotors last night, and it turns out you have to take a fair bit off the HQ rotors, you actually have to take them down lower than the minimum thickness by a few mm, However the VN V8 rotors are almost identical, just a little larger. If you buy the DBA rotors you can have them as blanks and then drill them to your own stud pattern...
Making up the bracket is not really an issue, the hardest part will be getting the depth right, but if i really wanted to make it look perfect i'd just give the job to an engineering works
My main concern is having heard a few different reports of the calipers not being the best performers, apparently they are better than alot of old calipers, but some say the HQ pbr cast iron units are better, im starting to think i should stop wasting time and just look into a newer twin piston setup. If i fit up something like a BA twin piston, it'll be fairly easy to upgrade to Brembo 4pot if i ever decide to get bigger rims

I just liked the idea of doing the 4piston calipers on the cheap

[Rocket]

Blimey, you mean to say that my pedal would then move 2" instead of it's current 1".lol. Actually that would be better. Checked with a brake bloke today and he says that you can machine the HQ rotor down further for the Volvo caliper. But you cannot do it for the HQ caliper. This is because if your pads are almost worn out your pistons would travel to far & fall out of the caliper.
Rocket

[John Abbott]

Hey Matte...When we used to own an old 240 volvo, i used to go around to a volvo wrecker just near me for parts. He told me that he had a big demand for the volvo calipers from a place that use to do brake upgrades on the Holden HSV's. Apparently the volvo brakes were heaps better than the holden ones.!!!

[MaTTe]

Rocket, haha if you only have 1" of travel then i think you NEED this conversion...... haha
My brake pedal has about 2-3inches of travel which is about where i like it, good feel, dont throw you thru the windscreen the second you touch the brakes, but still have stopping power. Any more than that would feel too unnerving when you need them in a split second.

Yeah John, that sounds about right, i was reading a thread on another forum last night detailing how bad the VN brakes are, and some blokes were talking about fitting the volvo calipers to them to improve. Later some other blokes detailed how they then changed from volvo to HQ calipers to upgrade again

I'll continue looking into it because i have the calipers here, but i might just keep my options open