Saturday, 18 February 2012

Bleeding Brakes

This morning started with an investigation into the disk run out issue and play in one front wheel bearing hub. The answers in the end were simple but time consuming to identify and fix.

The play in one front hub was due to the hubs being custom machined and different to each other ! I have never been able to tighten one hub up enough to remove the bearing play, I had thought that I had damaged splines on the drive shaft CV joint or some powdercoat left on the splines. Well I stripped it all down and still couldn't see an issue. But by measuring everything I found that one hub has its centre bearing carriers about 4mm longer than the other - hence I couldn't close the gap - swapped it round onto the other drive shaft and all was well.

Incidentally although the front CV joints are reputed to be triumph 1300, they aren't, here's a genuine 1300 one, the splines are longer and the nut thread thicker

Then disk run out, if you recall I had  the new discs custom manufactured, however they weren't quite as original, the bolt holes for the hub to disc bolts were too shallow and the bolts were bottoming out, just breaking through the rear, as you can see in the following picture before clamping the disc up tight. Grind 2mm off the bolts and all was well, less than 5thou run out on each disc, spec is a maximum of 7thou so I was happy with that, as it was about 15thou before

So brake pads fitted, (I cannot fit the anti squeal shims as the discs are thicker than standard - when they have worn a bit I'll fit the shims)

Then onto brake bleeding, what a performance - this should be a simple job, but I couldn't get fluid through the system by pumping the pedal. In the end I applied a vacuum to the bleed nipples and sucked the brake fluid through. As soon as I had fluid at the nipples they then bled in the conventional manner, so now I have a nice hard brake pedal. During the bleeding process I noticed that the servo and maxaret abs valve made a nice series of wooshing and wheezing noises as the air circulated through the abs parts.

That done, new 13inch fan fitted and radiator installed.

Rather than pack the crankshaft pulley bolt out with spacers (as it normally goes through the VC for the fan) I sourced a new bolt which was an inch shorter than standard, for those stag owners who want to do this its 5/8th UNF 18TPI 3.5 inches long available from Land Rover dealers as it used in the suspension somewhere.

ATF transmission fluid also installed - although I checked the manual and it said capacity 8 litres so I poured in 8 litres, forgetting that it needs the gearbox pump to run to fill the torque converter, so I had a big puddle of ATF on the garage floor from the autobox breather - at least I hope its the breather!

Tomorrows jobs, adjust the handbrake and sort out the power steering pipes - then at last I can look at getting the engine ready for first start

8 hours worked today, grand total now 883

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