Thread: PAS Pumps and more pump questions.

Originally Posted by Lotz-A-Landies

I need to source a PAS pump to fit to a Stage 1 4BD1 and the only ones I can find are nearly $1K from Isuzu. There are currently a second hand one from the UK on ebay and a new one for a 4BD2-TC in the US also on ebay at less than $200 + shipping.

Will the later 4BD2 pump fit the 4BD1?

Or is there a less expensive option than Isuzu or their new truck dealers for the original 4BD1 part number PAS pump?

Air!

Most trucks run full air or air over hydraulic brakes, and the air for that is usually a gear driven air pump, removing the risk of a broken V or serpentine belt.

Are there any air pumps that can be fitted to the 4BD1 engine, without having to remove the vacuum pump on the alternator?

Can't help with the Air pump Diana, but we used a Landcruiser 60 series power steer pump on a 4BD1 fitted to a Defender, mounted above the alternator and just used a longer alternator belt. Works fine, the bracketry was a bit of a pain to make .
There are also Holden commodore (VK Black motor era, 1984/5 IIRC) pumps which would be easy to adapt, they utilise a seperate reservoir.

JC

I thought there was a standard gear driven PAS pump that merely bolts in place of a coverplate on the timing cover! That was all a mate had to do with his Perentie when he installed PAS on the 110.

Originally Posted by Lotz-A-Landies

I thought there was a standard gear driven PAS pump that merely bolts in place of a coverplate on the timing cover! That was all a mate had to do with his Perentie when he installed PAS on the 110.

Yes there is. IMHO this is the best option. I would have no qualms buying 2nd hand. A while back my PAS box started spewing all the fluid out - as fast as i could refill it!!! - out of necessity I drove for a few weeks with no fluid in the PAS system until I could fit a new box. I expected to need to rebuild my PAS Pump, but it still works fine!

THE_109 or someone else has a thread on rebuilding them - not hard to do.

There are a few slight differences, but I believe pumps from any 4Bxx or 6Bxx engine are interchangeable.

I believe I have seen some engines at wreckers with air pumps fitted.

Originally Posted by Lotz-A-Landies

I thought there was a standard gear driven PAS pump that merely bolts in place of a coverplate on the timing cover! That was all a mate had to do with his Perentie when he installed PAS on the 110.

There is, sorry forgot to mention this engine was originally a stage 1/ early truck version and had no provision in the timing case so another set up was required. Always the Isuzu gear pump is best, very reliable too. Everynow and then mine leaks a little of the fluid into the crankcase, but hasn't done so now for 12months or more.

JC

The Perentie RFSV has a dual cyl belt driven clutched air compressor but finding one is nigh impossible. I have been on the lookout for one for several years. Maybe one day when all the spares are sold off but don't hold your breath waiting. As said if your engine has the 3 bolt plate on the timing cover under the pump drive you can fit a gear driven ps pump from either a 4b or 6b engine. Some Stage 1 motors had no provision for the ps pump on the timing cover.

O.K. need to check my timing cover! Note to self: New task for Sat when on farm!

If it doesnt have one, can I swap the timing cover off a 6BB1, 6BD1 or later 4BD1 and fit the PAS or will there also be bits missing inside?

Just went through Dave's Isuzu CD, if I'm reading correctly all the 4BD1 supplied to JRA were code RB, RB01 and TRBG all of the three are listed as having the timing cover listed as diagramme 6-3 while this has different part numbers for the RB/RB01 and the TRBG all have the PAS facility. Hopefully this also means that the gears are there. now just need to find out if 8-97081999-0 the Isuzu number for the 4BD2 PAS pump will supersede 8-97078879-0 the pump for the 4BD1

Originally Posted by Lotz-A-Landies

O.K. need to check my timing cover! Note to self: New task for Sat when on farm!

If it doesnt have one, can I swap the timing cover off a 6BB1, 6BD1 or later 4BD1 and fit the PAS or will there also be bits missing inside?

I believe so, and all the bits are there AFAIK. The reason we didn't do it for this vehicle is the cost at the time, and availability of timing case etc.

JC

I have a spare timing cover if you need one. New. There are two types of PAS pumps maybe more. One allows room for double belt pulley the other doesn't. You should be able to pick up a pump from a truck wrecker.