1988 Isuzu Trooper diesel conversion

A few more shots of the tank installation.

The solution to the filler neck dilemma was to fabricate a tube to connect the new tank to the (shortened) original rubber fuel filler hose.

I began by ordering a piece of 1-3/4" I.D. mandrel-bent mild steel exhaust, something called a J-bend. This piece of tubing is used by custom header and exhaust fabricators and features a 180-degree bend and two legs of different lengths.

Next, I took a number of measurements of both tanks to determine the location of the filler necks on each. I used one of the mounting bolt holes on the tank flange as a reference point, as these holes were the same on both tanks. Using a straightedge and a long screwdriver (through the bolt hole, to obtain a reference line) I was able to measure the location of the necks fairly accurately.

These measurements were then used to generate a CAD drawing of the two tank necks. Additionally, I drew the J-bend and the rubber filler hose. All of this information was used to determine the best way to use the J-bend to connect the existing filler hose to the new tank. The CAD drawings were then printed and used as full-scale patterns to cut the J-bend, weld the pieces together and to cut the filler hose.

The filler hose was cut just after the first right angle bend (just as it begins to travel sideways after dropping from the gas cap area). The J-bend was cut into sections and tack-welded into an S-shape for initial fitting. After determining that the fit between the frame and bed support channel was too tight, I flattened the tube a bit in the middle in order to get it to fit. I also purchased a Gates universal 45-degree bent fuel filler hose, as I needed the 45* bend to connect the tube to the new tank's neck, which is at a more upward angle than the old neck.

My clumsy welding caused a burn-through during finish welding of the tube, so I coated the entire junction with J-B Weld to seal it. The final fit is extremely tight, but it works - leak free, so far.

The other difference was in the location of the overflow pipe. I had to bend it slightly sideways to get it to clear the body bed support channel, then buy a length of 1/2" I.D. fuel hose to connect it to the filler cap (the old one was too short).

The fuel tank I removed from the Trooper had very old gas in it. As a result, semi-solid residue was being drawn into the fuel filter, clogging it. I had tried to clean the tank, but it was obvious that there was a substantial amount of residue in the tank.

My options were to either have the tank professionally cleaned (quoted at $300 and up), keep replacing fuel filters until the problem went away ($25 each) or replace the tank with a clean one ($200). I decided to go with option 3 - that's the cost of 8 clogged filters, something I thought possible based on the condition of the old tank.

The problem: the new tank was not quite the same as the old one. Aftermarket tanks were no longer available from the suppliers I contacted, so I went with an OEM unit. It seems that changes were made at some point, however, as the new tank differed slightly from the old one. The main change was to the fuel filler neck location: the new tank featured a centered neck, while the old tank's neck was located toward the rear and angled back. This difference meant that the old fuel filler hose would not connect to the new tank, leaving me with no way to fill it.

As the 4JB1-T injection pump is on the driver's (in North America, at any rate) side of the engine, the factory gasoline fuel line termination at the passenger's side frame rail near the firewall had to be addressed.

I had initially run rubber hoses from the factory hardlines up and over the firewall, down the fender and to the filter/primer pump assembly. In search of a more permanent solution, I decided to install steel lines in place of the rubber hoses, following the same route.

The new lines are formed from 6' lengths of brake and/or fuel line and are secured along part of their route by the factory clips (one of which used to keep the clutch line in place when it ran across the firewall; the other was empty), one new bracket (connected to the cruise control actuator mounting holes and running up the firewall) and a few rubber line clamps.

The new steel lines connect to the factory fuel supply and return lines at the passenger- side frame rail with short lengths of rubber hose, and to the filter/pump assembly with loops of hose. I am not terribly worried about the proximity to the exhaust where the new lines meet the factory lines; although it is close, I plan on fabricating a heat shield if necessary.

After hard farm use and two years of sitting outdoors, the brakes on the Trooper were in poor condition - the calipers were seized (along with their mounting bolts), the rotors were rusted, the pad friction material had separated from the steel backplate, and the fluid was completely black.

I repacked the front wheel bearings and locking hubs, replaced the grease seals, had the front rotors machined and installed a new set of calipers and pads.

The rear brakes received similar treatment: new rotors, calipers and pads. I also lubricated the parking brake cables and pivot points, replaced one of the parking brake cables and adjusted the system. Fresh fluid completed the rebuild.