Bypass filter rave!

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Mar 10, 2019
melbourne, Oz
I am pretty wrapped upon installing a bypass filter on my 1988 hj75 2h. I was doing some big k's and changing oil frequently and always disappointed that the oil looked dirty very quickly, like I didn't change it after 100k's or so. As most of us, I want my tojo to last a long time, so we want clean oil.

I met the fella who makes the Jackmaster bypass filters here in melbourne and installed his Ultra filter with an oil return line which goes to the filler cap and draws dirty oil from a sandwich adapter before the oem oil filter.

It was pretty easy. Moved the starter relay to the left, the ip vacuum to the right (shares a bolt with the air filter mount) and there was a nice area for me to install the supplied bracket by using an original bolt hole and drilling just one hole.

On the sandwich adapter I installed an electrical autometer oil pressure gauge sender as well as a mechanical Marshall oil pressure meter. This way I could measure the two systems for good accuracy.
Do not trust the oe oil pressure gauge. Even after I installed a longer pressure relief valve replacing the pristine oe short valve (about 200,000 original k's, ex nsw fire truck) both the meters hit 100 psi at an easy rev between gear changes. So, I cut my spring 2 1/2 rings and I felt that it was a bit psi low so added a little ss washer to pack it out. She now runs at 50-57 psi when cold idling, lowest 37 psi idling after a 600k drive. At top revs of 3000 rpm she might get 82 psi, if I try hard. It is no wonder folks blow oe filters without doing something about the oe relief valve.

Bugger trying to fit some gauges behind the starter motor to the oe oil pressure sender. The sandwich gives excellent access. It is a superior system.

I was a tad concerned upon having return oil coming at the top of the block, but it is not much at anytime and allows excellent access to drain some oil when it is overfilled. I can even just swing the the filler cap over a measuring jug to get exact amounts, like 500mls, perfect.

I got a used oil filler cap from pickapart from an old tojo, $4. They are standard size for lots of tojo engines. (There is a guy taking every tojo engine out of the wrecks here, he must like them). Jack put the cap on his lathe for me and got dead center (important).

The hydraulic lines Jack supplies are an excellent design and totally flexible for how long you want to cut them. Very good quality

The engine is very happy, it feels smoother. The oil on my dipstick has never looked so clean. Very fine soot still gets through the bypass, but if you put this oil on paper and hold it to the light, the oil looks pretty clean for a 30 year old indirect diesel. Before the bypass install, the dirty oil had larger carbon deposits for sure. One can imagine the engine cleaning itself when observing the oil.

ew paper

There is a few mobs in the states making bypass filters. But Jackmaster was the simplest for me to find a sandwich which fit the toyota oe filter. I had to remove the filter mount to remove the inside through bolt with an impact. Cut a new gasket and back in action. That was the most difficult part of the install.

A few more pics in the next post, very happy.

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