Guzzi 1000 to Reliant Axle

[moorem]

Offering up the axle to the swinging arm frame from Fastrikes.
Everything slipped in just nicely.

[moorem]

Wheels on for a quick gloat.

[Manky Monkey]

That's a nice arse.

[moorem]

That's a nice arse.

Thanks. It would not be where it is now if it were not for MMM and its very helpful members.

[Manky Monkey]

  It's what we do.

[moorem]

Well its been some time since I posted an update.... family, holidays and kids off to university take priority but we have started again.

Well after my ancient switched DC welder blowing up on me, prompting the purchase of a new DC 150 amp inverter welder, we got the drive shaft welded together. I used the splined shaft from the Guzzi and welded a splined sleeve into an EN8 steel collar that was welded into a Reliant drive shaft. All very stable and welded with low-hydrogen rods so the well will be about as tough as I can manage from a home workshop.

It is handy being able to weld!

As soon as I can I'll post some pictures of the drive shaft.

Next up... brake hydraulics. We are opting for braided stainless flexible pipes from the Guzzi foot brake cylinder to drive the rear brakes via a T piece mounted on the rear axle. We found a company in Pitsea - Essex who will make them while you wait and he is about half the price of some other suppliers. I don't know how the feeling is about giving out suppliers details here so if anyone want to PM me then I'll send the details.

Again... more pictures to come in a little while.

Martin

[Manky Monkey]

Nice to see you back Sir & to hear things are back on track.
No problem if you'd like to recommend a company you've had good service from -we've got a section just for that. Check the Links for Commercial Purposes bit.

[moorem]

Back again after a break.
Got the prop shaft welded and in position. Original splined shaft driving a reliant stub through a splined male sleve welded into a boss. Seems to be OK. Checked the synchronising of the UJ's and by shear luck I got it right. I own up to not checking the spline alignment before fully welding the assembly. Not even half a spline out of line... phew that was close. I'd have hated to have had to try and cut that weld to reposition the boss splines.

[moorem]

Another view of the drive shaft from a different angle showing alignment back to the gearbox from the reliant axle:

[moorem]

Now to a problem and I'd really welcome some advice here.

Having had a fairly nice time with the disc conversion where everything went absolutely fine and dandy after some excellent advice from member I am stumped with a hydraulic problem.

The MotoGuzzi foot brake is a dual linked system. Front and back. I figured that with careful bleeding I might be able to get away with the cylinder being able to drive both rear pistons (now eather side) and of course the front as well.

It does but... the damn rear hydraulic pistons keep popping back in after the pedal pushes them out and so I have a very spongy brake pedal action.
I've bled it to bits and even inserted residual pressure valves either side leading to the rear discs. The calipers keep retracting though. When the foot brake it activated and pumped the pistons extend but then retract back in and so need pumping again.

Anyone any ideas please?

The picture below shows my attempt at inserting two residual pressure valves (2PSI) but the pistons still retract.

[Olds]

You should only need one valve and it should be as close to the master cylinder as possible. Don't recognise the make but I assume that they are fitted the correct way round.
One other thing, are you sure the calipers are mounted square to the disc face. If not, when the brakes are applied the mount or disc may twist slightly and when pressure is released they twists back forcing the pads out again.

[moorem]

Hi Olds....

I agree but I've had some conflicting advice. So I thought I'd go for the overkill advice first.
As far as I could find out these valves are usually installed where the master cylinder is lower than the slave. It should not be a problem with the Guzzi because it is much higher than the discs front and back.

The conversion is  GTI calipers as per MMM and for which I received excellent advice from the forum.

When I first installed the brake lines the rear brake pistons sprung back into the cylinders. I bled the lines to hell and back but the still insisted on springing back in.

Aha I thought... keep the pressure on. So I had the valves put in but the damn caliper cylinders, and particularly the right side, insist on springing back in after the foot brake is pumped. After it is pumped 3 - 4 times it grips but then you can see the pistons squeezing back in when the foot brake is released.

I can put a single valve back inline further near the master cylinder but I'm wondering if I'm missing a trick with the VW calipers. Might it be a problem of needing the handbrake applied for slack to be taken up as some self adjusting brakes do on other calipers?

This is the master cylinder by the way... 5/8" piston.

If you still think a single valve will work then I can try that.

Any more thoughts?

[Manky Monkey]

We put residual valves on my Pop, (I don't pretend I knew that was the problem. That was down to a far cleverer Monkey than me). The brakes were bleeding back overnight, so the pedal needed a couple of pumps the next day to bring it back up. We also fitted a one way valve. Would that help?

[moorem]

Hi Manky,

Thanks for coming back to me.
I don't think it is a draining problem because I can watch the rear pistons springing back in as I take my foot off the brake. I quite like the idea of a one-way valve though.

Martin

[Olds]

Sounds almost like the rubber dust ring is pulling the pistons back in. Are the calipers the correct size for the thickness of disc ? I'm not sure to how your calipers work as far as handbrake/adjustment goes but many have an adjuster inside the piston that is actuated by the handbrake. Try actuating the lever on the caliper a few times.
Problems like this are why I stayed with the standard drums. They work.