Line pressure question

Just finished rebuild C4 couple weeks ago. No governor or modulator fitted and is full manual VB forward pattern.(not transgo kit either)
Line pressure i'm told should be approx 200psi. My understanding is it should hold 200 pretty constant???????

Today i'm seeing 360+ psi cold in N,does drop down when warmed a bit to 200 at a low idle but as soon as revs rise slightly so does pressure to 300+ psi , in 1 and stall up a bit with oil warm idle is around 200,stall up a little seeing 290-360 psi. Looks like fwd clutch might have turn the diapram spring inside out with the excess pressures???
Have to get in touch with the V.B company monday


<font size=-1>[ This Message was edited by: gregaust on 5/19/07 6:46pm ]</font>

Wow...thats definitely getting up there isn't it???

Greg, just a point on the forward's spring, from your experience what do you think is the maximum pressure it can handle? Do you think it would be a good idea to cut a retaining groove and run a circlip (or something similar) to prevent it trying to turn itself inside out....especially if #3 thrust has been rollerised?

I don't know why a blank space is here.

<font size=-1>[ This Message was edited by: Stuarta on 5/20/07 8:30pm ]</font>

The addition of a clip or retaining ring would be stopping movement of the piston and spring.

The problem is not in the forward clutch.

Just to add Stuart. It has lost drive too, forward clutch is slipping bad . Reverse is fine. Thats why i thought maybe those pressures wrecked the diaphram spring in there for the forward clutch to fail. Those pressures are out of control. .. The problem is in the valvebody.

Chris around 200 psi is the go from what i've found,some VB go to 240. That would be my limit ..
Will have it out tomorrow and see what is damaged anyway .

The thing that keeps the diaphagm spring from travelling too far is the clutch free play. As long as it is within specs it won't over travel. (unless something breaks)
360 psi in the main pressure circuit? That kind of pressure will cause converter ballooning and possible band or case failure. Is the pressure regulator valve stuck?
Paul

Yes Paul it must be stuck.I didn't do this valvebody,i've been buying them already done lately converted to manual. They are a nice product just a small hitch with this one.

Clutch pack clearance i set at .030. BUT what stops the piston from bending the fingers of the diaphram way past where they normally go and then no apply of fwd clutch.

#3 thrust must stop the piston eventually....if its used and not rollered.
But I guess by that stage the damage is already done...

Will find out and follow up soon

I see what you mean about the over travel - there really is nothing there to stop the piston under that kind of pressure until it comes out of the bore and dumps the pressure - as has been said, "by then, it's too late."
looking forward to the update!
Paul