Clark C300-50 inching valve question

[Harleyhoracio]

The inching valve was pouring brake fluid out the front of the body. I purchased a new kit that contained 3 springs, rubber cup, metal cup and valve. I removed the old assembly, cleaned out the cylinder and reassembled. I pumped the pedal a couple of times and the fluid is still leaking from the front. Can anyone tell me why its doing that?
As evidenced by the lack of paint in that area, it appears to be an ongoing thing.

 

[TD24]

The inching valve was pouring brake fluid out the front of the body. I purchased a new kit that contained 3 springs, rubber cup, metal cup and valve. I removed the old assembly, cleaned out the cylinder and reassembled. I pumped the pedal a couple of times and the fluid is still leaking from the front. Can anyone tell me why its doing that?
As evidenced by the lack of paint in that area, it appears to be an ongoing thing.
View attachment 305918

Most likely the U cup is in backwards. You are applying pressure against it, not using it to pump down.

 

[Harleyhoracio]

Most likely the U cup is in backwards. You are applying pressure against it, not using it to pump down.

I'll check that, thank you.

 

[Harleyhoracio]

Most likely the U cup is in backwards. You are applying pressure against it, not using it to pump down.

Here's the way it came out of the cover. Does this orientation look correct? There's two springs doubled up on the end of the valve. Is this right??

 

[TD24]

O K,
Fluid is going by your U cup. In wrong or you did not clean you honing out well,
(in 13 years we never had to hone one).

Double springs are right (they default to push back when you release the inching brake, so you get a solid return). The other springs merely position the brass insert into the u cup to keep it flared.

Don't get upset, but that is the messiest - debris laden set of guts I have ever seen come out of a cover. Fluid terribly contaminated or honing residue still in the bore.

Get a cheap bottle brush and swab out the bore till it shines. Clean and examine the u cup closely.
If it is still firm and no visible nicks, reassemble per the attached pic and try.

Take a look at these...

 

[Harleyhoracio]

O K,
Fluid is going by your U cup. In wrong or you did not clean you honing out well,
(in 13 years we never had to hone one).

Double springs are right (they default to push back when you release the inching brake, so you get a solid return). The other springs merely position the brass insert into the u cup to keep it flared.

Don't get upset, but that is the messiest - debris laden set of guts I have ever seen come out of a cover. Fluid terribly contaminated or honing residue still in the bore.

Get a cheap bottle brush and swab out the bore till it shines. Clean and examine the u cup closely.
If it is still firm and no visible nicks, reassemble per the attached pic and try.

Take a look at these...

View attachment 306146

I know its bad. I've replaced everything in the brake system. Made new brake lines, new wheel cylinders, new master cylinder, new shoes and drums, new hardware...no short-cuts and no expense spared. If its worth doing, its worth overdoing in my book. That being said, I want everything right. I took a new battery cable end brush, cleaned out the bore and flushed it with some Xylene until I got clean fluid. I then used compressed air and blew out anything left behind and reassembled. One thing to note, I didnt see these parts, 06.476 and 06.477 when I blew out the bore. They could still possibly be inside the bore, I dont know for sure. When you suggested that I had the cup in backwards, upon removal of the new parts, I did have the orientation correct.
Side note, whoever owned this unit prior to myself, removed the parking brake handle, cable and assembly that's mounted inside the trans. They put one of those Mico Locks on it for some unknown reason. I'm not sure if the oem parking brake was ineffective or what, but the Mico Lock is plumbed into the system.

 

[Harleyhoracio]

Here's some pics of my crazy.

 

[Harleyhoracio]

 

[TD24]

Terrific job on the cleaning and restoration of the old girl. I recall the 2 # you ref on some old C50 Clarks, but do not recall having or using on the C300's. C300's are merely reproductions of the C model with a changed power steering system, alternator vs gen, and pedal connections. From bolts in the fan blade to the lugnuts on the drive wheels, still the same. Truck was revamped to offer as a cheaper truck than a C500 during the influx of Datsun/Toyota appearance on the market.

We always removed the brake line, unscrewed the big nut, removed the pin connecting to the shaft arm. Pulled it all out, screwdriver with a shop rag wound around to swab out the bore. Place the two stiff springs over the plunger/piston/rod(whatever you call it) and push it down the bore to protrude and fasten the pin to the shaft arm. Wet the u cup with fresh brake fluid, insert the brass expander, slide
it all in and push down/in with any round blunt tool to seat. Put in the finer tapered spring (small end down) to fit the brass seat. Screw on the big nut. Connect the brake line loose enough to bleed, hit the pedal twice to bleed, tighten it up good. All done.

90% of the need to repair this was one of the two springs deal would break, jam and would not return
you to drive. Most of the time, we opened it up, put in the two new stiff springs, the u cup, closed it up, bled and back to work.

But, ours were always clean and slick with clean fluid. Never had a bore scarred of pitted or rusted...should one of the springs be broken, pop a magnet down to remove loose remains.

Hope this helps....