Rear brake bush

[Gaz747]

Good morning ,

I am in the position of having to drill out the holes for the rear brake bushes , I am interested to know what size drill bit is favoured ?

The bushes I removed were a perforated metal like decried above.

[Parazine]

I think the brake bushes are 9/16" OD. You might want to drill slightly smaller, say 35/64" and ream to 9/16" to try to correct out of round drilling.

The accurate way of doing this would be to set the axle case up on a milling machine but it would have to be very large machine! Might be able to do it on a large, floor standing, very stout pillar drill. The problem would be chattering of the tool bit due to flexure of the axle case.

[Howard Wright]

Hi Gareth

I’m not sure why you need to drill out the holes.  I think bushes are available that are a straight fit.

Cheers

Howard

[Gaz747]

Thank you both for your replies .

Parazine I will give that a go , I hope to do it with the axle in place.

Howard I have a set of bushes which I have already fitted to the front however the hole on the rear axle is too small to take the same bushes .

I understand the perforated bush I removed to be a smaller variant and no longer available from looking at another thread.

[Ivor Hawkins]

Gaz, just as a precaution, have another close look at the hole, it wouldn’t be the first time I have seen a bush within a bush and there might be the remains of a very worn, very thin bush still in there!

[Gaz747]

Hi Ivor ,

Thank you for the reply .

I will have another look .

Cheers

[Howard Wright]

Hi Gareth

Sorry, I didn’t realise this thread was preceded by another on the same topic.  I would agree with Parazine in that ideally the hole should be milled.  Hand drilling is fraught with perils (don’t ask me how I know).  An alternative is to turn up a new phosphor bronze bush or turn down the outside of the bushes you have.  I know that requires a lathe!

Alternatively if you are intent on drilling out the holes I would use an adjustable hand reamer slowly increasing the cut diameter until you get it right. 

Cheers

Howard

[Jamie]

My front brake bushes were like that: one inside another. A standard modernbush fitted perfectly in their place.

Jamie

[Ian Williams]

The perforated bushes for this type of axle are no longer available so you need to either, open the holes out to fit the earlier size of bush, or get someone to turn you up a bespoke set of bushes.