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Saturday, March 27, 2010

tractor roll and tile

Rolled the tractor dragging a stump up hill. It wheelied spun to the side and rolled.
Operator and tractor are OK. It finished the job after being set back on its wheels. Operator error.
Installed tile at a 45 degree angle. Sue picked the color and pattern.
The harbor freight saw wasn't wide enough to cut 45's so I made extensions and a wooden guide.

Wednesday, February 10, 2010

Remote accumulator for Hydroboost

Hydroboost with remote adapter in place of the blue original. Charged with helium argon mix to test for leaks. It really should have nitrogen instead but I don't have any. Accumulator is made of titanium.
Gauge adapter and charging valve. Charge valve is a schrader like a tire fill valve but has no guts. One of the nuts moves the stem and seals it. Accumulator tag came with it and shows it came off Northwest Airlines tail number N1161US 5/06 when it was scrapped. I googled that aircraft and it set a speed record Feb. 96 from Washington DC to Amsterdam. you never know what google is going to come up with!

http://records.fai.org/general_aviation/aircraft.asp?id=200

Sub-class : C-1 (Landplanes)
Speed over a Commercial Air Route : 993.13 km/h

Date of flight: 17/02/1996
Pilot: David J. ROTH (USA)
Course/place: Washington, DC (USA) - Amsterdam (The Netherlands)

Aircraft:
McDonnell Douglas DC-10-40
Registered 'N1161US'


I'm holding the gauge adapter made from 3/4 round CRS. The external threads are kind of a reverse O-Ring boss style fitting. Threads are 7/16 X 20 and the angle of the O-Ring seat is 11 degrees. The other end is tapped 1/4 NPT for the gauge. Getting pipe thread to seal at these pressures was kind of a tussle. Ended up using 320 grit lapping compound and a pipe nipple to lap them in. The original gauge was no good.

Sunday, January 31, 2010

Hydroboost remote accumulator adapter

The silver adapter replaces the accumulator and has a JIC fitting on it for a remote accumulator. It fits in place of the original like the gold one on the left.
Used a small block chevy valve spring to hold the adapter against the lock ring. The original was held in place by the gas pressure. An O-ring seals it.

Made dimensions the same as original.

Monday, January 25, 2010

Hydroboost accumulators and a BBQ tour

The bigger silver accumulator is what I'm going to adapt to the hydroboost. It is 3 to 5 times larger in capacity than the stock size units on the left. Removed from a DC-10-40 when it was decommissioned.
We went on a BBQ tour, Missouri, Tennessee, Arkansas, Oklahoma. The ribs we got in Missouri were the best.
Missouri mines state historic site. Missouri has a lead belt and this mine was turned into a museum with a huge collection of minerals from all over the world. There are hundreds of miles of tunnels now flooded. The Doe Run mine is in operation today in the area. Located by Park Hills on highway 32.
Beale street Memphis Tennessee
Martin King museum. The cars are like the original ones that were parked there.

Friday, January 15, 2010

AN6 adapter fittings

These fittings adapt the metric oring ports on this booster to AN6 which is the same as common JIC hydraulic sizes.

Another view of the "two function" valve

Wednesday, January 6, 2010

Hydroboost, snow and a wallowed out hole

Bendix uses a figure eight seal ring. It is not round and is almost square in cross section.
Body halves ready to go together. I found that the power pistons are different in depth where the master cylinder push rod seats. I made two out of 3/8 bolts to get one I liked.
Forecast 6 more inches of snow today. My back blade angle locking pin hole is wallowed out.
Welded on a ring to take some of the slop out.

Monday, January 4, 2010

Hydroboost seals and valves

Some boosters have relief valves. The top left one doesn't and is the 94 Astro unit. They look kind of like sight glasses from the out side. There is some clear hard stuff and a blue plastic ball stuck in the hex socket that adjusts it. Not supposed to be user adjustable haha. I think I read that they are set for 1,600 psi. In my case it was 9 turns in from the first thread when removed so that's where it will be reset.

Here is the valve and spring out of the hole. An O-ring seals it
This is the "two function valve" the yellow end lets pressure in the accumulator if the line pressure is higher than what's in the accumulator. The pin lets fluid out of the accumulator if hydraulic line pressure is lost and the pedal gets mashed far enough to push it in. That is the emergency back up.
The hat looking piece is what pushes the pin in.
Spool body plug held in with a spring clip and seals with an O-ring.
Power piston seal.

Thursday, December 31, 2009

Hydroboost measurements


-----------------------------94 Astro ------------99 Astro ----------------Dodge

Input rod -------------------.595 -----------------.595-------------------- .545

Power piston ---------------1.56 -----------------1.56-------------------- 1.56

Lever ratio------------------- .62------------------ .62 -----------------------.73

Stock pedal ratio ---------dunno ----------------5.2:1------------------- 4.2:1

All of these had the bigger power piston. The Dodge unit had the smaller input rod for more gain and the 73% lever for more relative motion of the valve spool.


Here is a pic of the Dodge pieces on the left compared to the 94 Astro. You can see the difference in the lever pivots. I can't tell any difference between the valve spools.

The GMC steering pump is supposed to be set at 1,400 psi. If I did the calculations right this would be 2,675 lbs of force to the master cylinder with a power piston 1.56" diameter and 1.911 square inches in area. This would be with an input rod force of 326 lbs with a rod dimeter of .545" and an area of .233 square inches. The force at the pedal with the GMC's stock 4:1 pedal ratio would be 82 lbs. All of this would make 2180 psi brake line pressure with a 1.25 diameter master cylinder. Way more than the vacuum booster.

Tuesday, December 29, 2009

Hydroboost kit and input rod seal installer

Got a hydroboost repair kit from Restoration Perfomance Center in Arizona. They had the best price.
These input rod seals have to stretch over the threaded rod and piston and not get torn up. They have to stretch a bunch... I made a two part tool with a sleeve and taper piece. The sleeve slides over the threads and end of the piston keeping the seal protected.
Sleeve and taper tool parts.
Got them on OK. Old seal on the sleeve.
The old seals tore stretching them to get them off.

Sunday, December 27, 2009

Snow and a John Blue pump

We got a blizzard Christmas day.
This John Blue pump was made in the 50's for LPG or anhydrous ammonia transfer. It has a piston motor that operates off of the difference between tank pressure and atmospheric and drives an attached piston pump that moves gas from one tank to the other creating a pressure difference. The transfer is done by a separate liquid line between the tanks. Some gas is lost to the atmosphere from the motor end in normal operation. The motor valve shifter had broken and it took a while to figure out how it went back together and what the parts were supposed to look like. Originally they were used to transfer anhydrous from a bigger nurse tank to a tractor mounted tank when tractors could not carry so much weight.

Tuesday, December 22, 2009

Snow blower fixit

They don't make them like this any more, 4 stroke chain drive and very little plastic. The starter recoil spring had come unhooked because one fastener loosened up. Put in a new plug, changed oil, lubed the chains and it's good for the big snow in the forecast and for more years to come. Below is a short movie of it starting and running...almost gets away from me in the back of the truck.

Monday, December 21, 2009

Accumulators on the hydroboost

I'm using the caveman c-clamp method of compressing the accumulator so the lock ring can be removed. There is an official tool for this but I don't have one. The pin punch fits in a hole that pushes the lock ring in enough to fish it out with a seal pick. The accumulator goes in about 1/8 inch against the stop in the housing. If the nitrogen is gone the accumulator will wiggle in the housing as there is no pressure pushing it out...one test for a bad accumulator.
There is an O ring that seals the housing to the accumulator. The lock ring is at the bottom of the picture.
The blue accumulator is for disc/disc brakes charged to 450 psi and the gold for disc/drum brakes at 350 psi. Gold is the type needed for our GMC with original brakes. There are other types of these, some remote mount types and at least one using a spring instead of nitrogen for pressure.
A view of the housing with the accumulator removed.

Tuesday, December 15, 2009

Hydroboost Heaven, a tale of three boosters

Scrounged up three Bendix hydraulic brake boosters to maybe make one like I want. The top one is from a 99 Astro van, center Dodge flatbed and he bottom from a 94 Astro. Don't know what year the Dodge was as it was pretty much stripped. It was a gasser and had a long frame. Notice the angle of the 99 Astro mount plate and master cylinder. Maybe it will work better for the GMC. The blue and gold cylinders are accumulators with a nitrogen charge. Gold is for disc/ drum brakes charged to 350 lbs and blue for all disc brakes charged to 450 lbs. I'm looking to assemble a booster with a 1.56 power piston, .545 input rod and a .72 ratio lever. This will make a booster gain of a little more than 8 to 1.
The Dodge had a goofy angle adapter on the master cylinder end.
Angle adapter removed, now it has a pattern like GM uses.
Custom caveman square tube wrench used to remove the mount plate on the pedal end.

As Geico says a caveman can do it.
The input rod has to be cut in order to get it apart.
One solution is to thread the rod so any length extension can be fitted with whatever needs to be on the end to connect the pedal.