240 Hydraulic Clutch Conversion

[Cameron]

I am converting a 240 from cable to hydraulic clutch and am short on 1 piece of the puzzle...

I don't have the "stock" 2 piece line between the master and slave cylinders and I am not planning on hunting that down or paying dealer price for it. What I'm coming up short on is the size/style of the fittings on the master and slave.

I am using the 260 master cylinder and 740 slave. Planning to run a -3 line and would like to run a banjo fitting off the master for cleanliness and compactness as the master sits pretty close to the strut tower so there's not a lot of room for adapter fittings and hose end off the end of it.

Measuring with a thread pitch gauge, both appear to be 12mm x 1.0 thread pitch. I'm having a hard time though finding a 12x1.0 to -3AN adapter. I find -3 to 12x1.0 bubble flair adapters and can find a handful of stuff that's 12x1.0 in other various flare fittings. My question is, do the flare ends really matter if the thing gets sealed with copper washers?

What did you guys that have swapped to hydraulic clutch use for the hose? Or am I better off just taking both the master and slave to a hydraulic shop and telling them to make me a hose to go between them to X length? Which of course I should have thought of before bolting in the master

[ryanfay]

I would personally go to a hydro shop. Those DIN fittings are rare, but still sourceable. You could adapt to an AN (JIC, not redundant an AN), but if you go to an adapter, then you would still have to pay for the AN fittings on the line anyways.
Besides DIN 24 (which is what I believe youre talking about) seals way better than any copper washers.
Nothing worse than a leaky clutch linkage, ask me I know.

Ryan

[ryanfay]

My bad. The slave does have a flare but a M10x1 I thought. hm..

[Captain Bondo]

The 740 turbo hose bolts right in. It used the same fittings as the brake line M11x1.0 IIRC - metric extra fine.

The flare is a standard metric double flare. Seriously though just use 740 stuff.

[DNAsEqUeNcE]

1

[Cameron]

Originally Posted by ryanfay

I would personally go to a hydro shop. Nothing worse than a leaky clutch linkage, ask me I know.

Ryan

Yeah, trying to avoid leakiness or having to redo it. I'd rather do it right, do it once.

Originally Posted by ryanfay

...M10x1 I thought. hm..

That's what I thought it was but M10x1 is way too small for the hole (that's what she said).

M12x1.25 starts to thread in, but threads aren't fine enough.

Originally Posted by Captain Bondo

The 740 turbo hose bolts right in. It used the same fittings as the brake line M11x1.0 IIRC - metric extra fine.

The flare is a standard metric double flare. Seriously though just use 740 stuff.

Same fitting size on the 260 master and 740 master too? So the hard line and flex line assembly from a 740 would work overall then you're saying? If so that would be fine with me as the 740 clutch lines are waaay cheaper from Volvo than any of the 260 hoses.

Thanks for the insight/experience dudes

Edit: Looks like I can order all the parts (hardline/fittings/flex line/etc.) from Volvo for like $75.00 brand new which is a lot more palatable than the pricing for the 260 stuff. Flex line is the same part # between the 2 cars, but the hardline price is about 3x as much for the 260 one vs. the 740T one which is pretty dumb if the only difference is the length of the hose.

[JW240]

I used a 260 MC combined with 940 hose/hardline (same thread/length as 740 stuff just tube crimped to hose, no coupling there) and 940 slave. It is all M12x1.

good luck on finding M12x1. Over here in metric land it is hard to find even. Some old Barkas vans used M12x1 threaded brake lines but it has been a long time since i looked into that option. You can find M12x1 banjo bolts on some 80-s VW brake systems too but a banjo coupling wont help you much.

I would try to get it via a hydro-line shop and keep the 740 line option in mind as a backup.

[Captain Bondo]

Originally Posted by Cameron

Same fitting size on the 260 master and 740 master too?

Yes. 740 hard line screw right into the 260 master cyl.

So the hard line and flex line assembly from a 740 would work overall then you're saying? If so that would be fine with me as the 740 clutch lines are waaay cheaper from Volvo than any of the 260 hoses.

Yes and yes. The 740 hard line has a bracket that fits perfectly, it gets attached via the rearward of the 2 front crossmember bolts.

[Cameron]

Originally Posted by Captain Bondo

Yes. 740 hard line screw right into the 260 master cyl.

Yes and yes. The 740 hard line has a bracket that fits perfectly, it gets attached via the rearward of the 2 front crossmember bolts.

Bitchin'. Thanks for the clarification

[sbabbs]

Here's some pics of the 740 hydro setup.










Not sure why but this part makes me feel so gay..

[Captain Bondo]

Installed w/ bracket on 240:

[sikbrik]

I'm no help, but what are you using for a pedal? Modified stock pedal or the last 260 pedal on earth or...??? Thanks!

[nathaninwa]

I ran the stock hard line from the master to the frame, then welded a dash 3 fitting to the ends where the rubber went, if I remember right I cut the metal ends off the hose and welded them there, then got a dash 3 brake hose for a chopper at the cycle shop.

[Captain Bondo]

Originally Posted by sikbrik

I'm no help, but what are you using for a pedal? Modified stock pedal or the last 260 pedal on earth or...??? Thanks!

Modified stock (cable pedal).

You can pretty much cut off the arm that the clutch cable attaches to and weld it back on uoside down, so it's a "push" instead of a pull.

The hole in the pedal box where the hydro pdel would mount is pre-drilled into all pedal boxes I have seen.

You then need to extend the pedal itself about 3-4". It sounds complex but once you are under there looking at it all it's pretty straight forward and is totally doable with a basic crappy 120v mig welder if need be.

I thought I had pics but can't seem to find any...

[smithy]

Did 240's come out with a cable clutch? In Oz we only had hydraulic clutches.

[Hen]

I think all LHD 240s were cable. Consider yourself lucky that Australia got only hydraulic.

Just confirming that both clutch master and slave threads are M12x1 (and almost impossible to find fittings for). At least on the 940 gear I have. I'd strongly recommend the Bondo suggestion of stock 740 line, seems very simple.

I've got some pics up of my clutch conversion here.

[M.H. Yount]

"....which is pretty dumb if the only difference is the length of the hose." The other difference is the old supply/demand factor...

[Cameron]

Originally Posted by sikbrik

I'm no help, but what are you using for a pedal? Modified stock pedal or the last 260 pedal on earth or...??? Thanks!

Originally Posted by Captain Bondo

Modified stock (cable pedal).

You can pretty much cut off the arm that the clutch cable attaches to and weld it back on uoside down, so it's a "push" instead of a pull.

The hole in the pedal box where the hydro pdel would mount is pre-drilled into all pedal boxes I have seen.

You then need to extend the pedal itself about 3-4". It sounds complex but once you are under there looking at it all it's pretty straight forward and is totally doable with a basic crappy 120v mig welder if need be.

I thought I had pics but can't seem to find any...

This is exactly what I did. Got a modified pedal from Tom Smith, which you can see it built just like Bondo describes:

Originally Posted by Hen

I'd strongly recommend the Bondo suggestion of stock 740 line, seems very simple.

That's exactly what I ended up doing.

[MrBill]

Good info. I just recently pulled the entire setup from a 260 with the intentions of installing it in my 244.

[24DinCT]

Could you not get a hydraulic shop...or performance tuning shop to get a you a SS braided line of the correct length and put the correct ends on? I know this is probably going on one of your project cars...so add some bling while you're at it!

[Captain Bondo]

Originally Posted by 24DinCT

Could you not get a hydraulic shop...or performance tuning shop to get a you a SS braided line of the correct length and put the correct ends on? I know this is probably going on one of your project cars...so add some bling while you're at it!

Indeed. In reality though, you could also just use a regular brake flex line for a 240 and cobble a setup from normal brake line parts available from any 240 at any junkyard for next to nothing
The fittings at the slave and master are normal 240 brake line fittings.

[dbarton]

Originally Posted by Captain Bondo

Indeed. In reality though, you could also just use a regular brake flex line for a 240 and cobble a setup from normal brake line parts available from any 240 at any junkyard for next to nothing
The fittings at the slave and master are normal 240 brake line fittings.

Can you clarify this? Below pic is a comparison of the flexible hydraulic clutch hose (top) and 240 brake line (bottom). They are not the same.
Dave B

[JW240]

Originally Posted by Captain Bondo

Indeed. In reality though, you could also just use a regular brake flex line for a 240 and cobble a setup from normal brake line parts available from any 240 at any junkyard for next to nothing
The fittings at the slave and master are normal 240 brake line fittings.

on my cars (with 260 MC and 700/900 series stuff) the clutch stuff was all M12x1. Line diameter was about the same though so its possible to make an adapter tube by fitting M10x1 and M12x1 to the same hardline though.

[Cameron]

Bumping for another question on the conversion. How extended or squished should the slave cylinder pushrod be in "resting" position?

I just got my motor in and mated up with the M46 that I pre-rigged for hydraulic clutch. With the release bearing & fork in place and the motor bolted down to the trans the fork all feels correct and seated and stuff, but my amateur eye seems to think it doesn't look squished enough? That is, it seems like the pushrod is pretty far out and like it might not have enough travel to fully push the release bearing into the pressure plate to release the clutch?

I guess what I'm wondering is, how much does the pushrod extend when the pedal is pushed to release the clutch? 1"? Less? More? I don't have the clutch hard line made yet so I can't just push the pedal to verify clutch disengagement yet.

I did some searching and did find this pic of Bergen's car from underneath with hydraulic clutch. My slave cylinder actually looks pretty much just like this with everything installed:



Is that just normal pushrod extension out of the slave cylinder at rest? I'm probably just worrying about nothing....

[Captain Bondo]

Looks about normal with a new clutch disc.

I have had to patch up cars that had a slightly bent fork and/or lazy slave cylinder when they got new clutches.

What you do is drill out the divot in the end of the clutch fork where the end of the slave presses, and install an M8 allen head bolt. Attack the end of the allen head with a decent sized drill bit to open it up a little and make a nice divot for the end of the slave to live in.

Use two nuts to attach the bolt to the clutch fork. You can thread the bolt
forward/backward to get the slave's resting position where you feel comfortable.

Just keep in mind that as the clutch disc wears, the slave needs to be able to RETRACT MORE. If you modify it, beware of the fact that if the slave were to bottom out as the clutch wears, you'll kill the clutch eventually.

The mod I suggested can be done in situ if necessary. So just try it first and see if it releases fully.