Trouble bleeding brakes (still spongy)

[takai]

If you simply unbolt the caliper and rotate the disc so they are upright it will work. Ive had to do that before on other cars. Just make sure that the caliper doesnt slip off the disc....

[o_man_ra23]

If you simply unbolt the caliper and rotate the disc so they are upright it will work. Ive had to do that before on other cars. Just make sure that the caliper doesnt slip off the disc....

As per my previous post... definitely a 2 person job.

Cheers, Owen

[CrUZida]

Yeah, i was thinking exactly the same thing. Without having the connecting channels at the highest point in the cylinder you have effectively created an area where there can be multiple air bubbles.

As seen in this really hella dodgy photoshop image:


The areas in pink are your problem

Thats EXACTLY the conclusion I came to this morning.
I was about to do a dodgy paintshop image too, but then I saw yours.

Above is the problem, caliper needs to be vertical.
Its as simple as that.

[CrUZida]

If you simply unbolt the caliper and rotate the disc so they are upright it will work. Ive had to do that before on other cars. Just make sure that the caliper doesnt slip off the disc....

Yes, that is the plan.
Problem is that my engineer will not accept this as a permanent solution.
If I can't bleed the calipers on the car, he won't sign off on it.



Oh, and Stu, I'm pretty sure the above picture is what you were getting at with the fluid channels.

[JustCallMeOrlando]

Dude, seriously, the angle isn't that much bigger compared to mine. Mine is NOT vertical. If we can get the back high enough surely we can get the air out.

[takai]

The main problem is that the channel is towards the bottom of the caliper. Towards the mounting bracket. I just checked my R32 calipers for reference, and from memory the R33 ones are pretty much the same location.

[CrUZida]

From a quick calc (guessing some figures I can’t remember), my calliper is ~40deg further rotated than stock.

Given a 3 metre wheel base, we’d need to lift the rear of the car 2.3 metres in the air to get that calliper vertical.
The HIGHEST I can get the car with a jack is about 0.45 metres, which would level the calliper by 9degrees.


My driveway however, is roughly 30deg angle, so providing its not pissing down with rain, its feasible.

[JustCallMeOrlando]

It would be in the spirit of Toymods to do it even it it's raining. Of course, i'll be in the car

[CrUZida]

Of course, i'll be in the car

I'll make sure the windows are down.

[takai]

It would be in the spirit of Toymods to do it even it it's raining. Of course, i'll be in the car

I'll make sure the windows are down.

Sounds fair.

[JustCallMeOrlando]

Fine, get your cabin wet. I can still wear protective clothing, you have to lay in it

[Hen]

A slightly related question, but why the big angle?

If it is the angle that is causing the problem is there any reason you cant remanufacture the mounting plates so the caliper sits more vertically?

Hen

[JustCallMeOrlando]

Due to the length of the caliper legs and size of the rotor, the bolt holes for the caliper and the spacer have to be offset to fit.

[oldcorollas]

Oh, and Stu, I'm pretty sure the above picture is what you were getting at with the fluid channels.

yup...

you might be able to lessen the issue by slotting the holes such that you don't need quite as steep angle to bleed.. ie so you can do on driveway...

do you have a spare set lying around to look at? i have some here, but i couldn't be arsed unless you don't have any (can't get the room dirty )

[CrUZida]

Nah, no spares to play with, not yet anyway.
Worst case I rotate it vertically.

And Hen, the reason for rotating the caliper was two fold.

Firstly, I had some prototype adaptors made up to keep the caliper vertical.
As per these pics.
http://toymods.net/forums/showpost.p...52&postcount=2
When I bolted it all up like those pics, the bolts were too close together for my liking.
It was very hard to get a socket in there to tighten them up.
So it was decided that rotating was needed.

The second reason was that I already had a set of new brake lines sitting there, that would fit with the caliper in the rotated position, but not in the vertical position.
So that was a huge bonus.


I've now realised that I can push the caliper ~2mm further outwards, and that should provide enough clearance between the bolts to do them up properly.