Technical Topics No. 10

A fairly common problem with Jackaroo brake calipers, and possibly other makes too, is seizing and or binding of the guide and lock bolts because of the the ingress of water and dirt. Several members of the club have already experienced this themselves. These bolts can become so tight that they actually break when trying to remove them. This then becomes a fairly expensive exercise in having them replaced.

These components are often overlooked during any routine maintenance, as the only time you would normally touch them is when replacing the brake pads, and as the life of the pads can be greater than the time taken for the bolts to seize, it is then often too late. As far as I can determine, they are NOT mentioned in any regular service schedule.

It is a fairly easy job to check these and, from experience, they should be checked at least every 10,000kms. If you have done a lot of water crossings I would check them even more often.

To promote trouble free operation;-

1. Thoroughly clean all dirt etc. from around the caliper guide and lock bolts,
2. Remove and thoroughly clean the guide and lock bolts from each caliper every 10,000km (or even sooner if doing a lot of water crossings), If they are corroded or show any signs of pitting, replace them.
3. Check the associated little rubber dust boot for splits or cracks, (replace if necessary),
4. Coat the bolts with a brake caliper lubricant, such as *CRC "Sta-Lube synthetic brake caliper grease".
5. Replace the bolts and boots but do not **over-tighten. (Note the guide and lock bolts are different, so it is probably better to do one at a time so that they go back in the correct position). Ensure that the boots have been seated correctly into the caliper housing at one end and the groove in the bolt at the other.

* Check this website for further information on this product.

** The specified torque for the bolts is 74N-m, or 7.5kg-m, or 54 lb-ft for the front calipers and 44N-m, or 4.5kg-m or 32 lb-ft. for the rear calipers.

This series of technical articles is of a general nature. The views expressed are not necessarily related to the Jackaroo, or any other make or model of vehicle. The content is believed to be accurate, but no responsibility can be accepted for errors or inaccuracies. If you have a problem with your vehicle you should consult a competent mechanic.

Return to top of page.