Inside Dimns.

[audrey]

I am trying to make up some new Hydraulic Cylinder replacements for a friends Bulldozer. (Very Old Thing) I need to figure out how to measure the end Gland Or Cap as you might call it with all the seals in it. Is there sopmething I can heat and pour in and then use an optical comparator to make up a Blueprint so as to make a new piece. Thanx audrey

[alumtuna]

Audrey,
Before you machine make sure u have the replacement seal with you. This would dictate the size & tolerance that is applicable to the design. Seals manufacturers have numbers that you could machine to & should follow (ie from where on a shaft). Your shaft will follow a fractional size.

[Thrud]

audrey:
If you are stuck, there is a compound sold called "repro-rubber" that is a silicone rubber molding compound used in metrology to measure complex parts. Most of the big distributors sell it (J &L, Travers, KBC, and others) - it is very expensive to just "play" with so use it sparingly.

You do not need to measure it with the seals in place, when you purchase seals for the size of shafting you are using ask for proper groove dimensions for those seals - they will probably just give you a seal catalog with everything you need in it.

[docsteve66]

Audrey, If the Dozer is very old, It probaly uses chevron seals. You buy it by the foot, size based on rod diameter, stuff it in like the packinging you pulled out and you are good to go!

Even if the glands fit sloppy, pack 'em, fill it up and see if or where it leaks. Same thing on pistons. they probably use packing around the piston and O rings where the rod goes through the piston. If The cylinder is not scored, you should have NO problmens attribuatable to the cylinder. If the cylinder "leaks Down" (and internal leak, sus[ect the valves.

On those stubb shafts, I advise, keying the shaft and its hub. I have actualy directed that we weld broken things together to get a job done, knowing full well I just tripled or more the cost of reapairing. But if the shafts are really worn beyond use then key/or weld them to see how the rest of the machine runs. Bad idea to fix one part at a time. Get it cobbled up so you have an idea what is good and how much work/money will be neeeded to fix the rest.