It really sounds like some sort of anti-lock brake mechanism, but I am at a loss.

As a matter of a general place to start, I would bleed all 4 corners and take a good look at the calipers and pads.

Michael

IF YOUR TRUCK HAS REAR DISC BRAKES , THIS WONT APPLY, BUT IF YOU HAVE DRUM BRAKES , CHECK THE REAR BRAKE ADJUSTMENT , FIRST MAKE SURE THE HAND BRAKE CABLES ARE NOT TOO TIGHT, AND THEN ADJUST THE REAR BRAKES UP TIGHT ENOUGH TO COMPLETELY HOLD THE DRUM AND THEN BACK THE ADJUST MENT OFF UNTIL THE DRUM WILL JUST BARELY MAKE A SWISHING SOUND AS IT IS TURNED , USED TO SEE THIS PROBLEM ON THE OLD KS22 TRUCKS ON A GRAVEL STYLE WASHBOARD ROAD WHERE THE REAR AXLE WOULD GET TO JUMPING UP AND DOWN AND WITH THE REAR BRAKES A LITTLE TOO LOOSE AND THE LSPV VLV LINKAGE SET TOO TIGHT OR BINDING IT WOULD DO THE SAME THING , PEDAL WOULD GO DOWN AND THEN A COUPLE OF PUMPS AND GOOD HARD PEDAL, JERRY

Yip, I have drums at the back.

Thanks for the feedback, my van is due for a service, so I'll have it looked at. I'm not happy with the performance of the brake system in any event ...

Hmmmm....

Do you know what axle you have in the rear? I'm just curious.

Does it have a removable cover on the back? Is the pinion/center chunk bolted into the axle housing from the front?

I'm just curious, because Isuzu has not used drum brakes that much (in relation to other axles) since 88. Yes, Randii, I am sure you own some strange configuration. <img src="/forums/images/graemlins/smile.gif" alt="" />

And, now that we know it has drums, I'll definitely drop the hunt for any ABS.

Michael

Hmmmm....

Do you know what axle you have in the rear? I'm just curious.

Does it have a removable cover on the back? Is the pinion/center chunk bolted into the axle housing from the front?

I'm just curious, because Isuzu has not used drum brakes that much (i

Michael

The rear cover can come off, It is also equiped with a vacuum triggered diff-lock. Not sure about the pinion :S



Sorry about the quality, taken with my mobile ...

I'm not sure which axle is installed at the rear, but it is the same as the axle on the TF140 range of 1-ton pick-ups with the local diff-lock added.

Ok, my van was in for a service. The service centre contacted the dealer service centre. According to the dealer service centre it is a well known problem/issue with the Isuzus in South Africa. They were not willing to divulge the solution for this. <img src="/forums/images/graemlins/angry.gif" alt="" />

In the meantime I'll try and find the balance between the rear drum brakes and the hand brake to see if it will solve the problem.