Brake Caliper Upgrade

[Bob_Spidell]

DW has a 'BJ8 Stub Axle Conversion:" https://www.bighealey.co.uk/performance/austin-healey/suspension-1/front-suspension

I'm totally confused by this; are they offering an earlier-style axle with bearings to fit, or something else?

 

[HealeyRick]

DW has a 'BJ8 Stub Axle Conversion:" https://www.bighealey.co.uk/performance/austin-healey/suspension-1/front-suspension

I'm totally confused by this; are they offering an earlier-style axle with bearings to fit, or something else?

DW's stub axles were designed to fit the earlier disc brake cars. The caliper mounting brackets on those cars bolted on and fit calipers with 3.25" between the mounting ears. The bearings on these cars were different than the BJ8 (larger on the BJ8, I think, but not positive) It looks like they have machined their stub axle for the BJ8 bearing and provide a mounting bracket that will mount the BJ8 caliper with 3.5" between the mounting ears.

 

[steveg]

DW's stub axles were designed to fit the earlier disc brake cars. The caliper mounting brackets on those cars bolted on and fit calipers with 3.25" between the mounting ears. The bearings on these cars were different than the BJ8 (larger on the BJ8, I think, but not positive) It looks like they have machined their stub axle for the BJ8 bearing and provide a mounting bracket that will mount the BJ8 caliper with 3.5" between the mounting ears.

Here's my understanding of the DW stubs:
Pre-late BJ8 stubs are weaker than the latter, esp in racing - many show cracks when tested; replacing these with BJ8 stubs is not an option as they're very rare.
Therefore, DW has built stronger replacement stubs which can be used on all cars. Their stubs can accept brackets with either 3.25" or 3.5" centers.

 

[HealeyRick]

Steve,

I think we're saying the same thing. DW has three types of stubs, advertised to be stronger than original. One for the BN1 (and 100S). One for the BN2-BJ7 and the third for the BJ8. As far as I can tell, the only difference between the BN2-BJ7 stub and the BJ8 stub is the machining for the wheel bearings which are different on the BJ8. Again, the caliper mounts which are bolt-on will differ according to the caliper being used.

 

[steveg]

Steve,

I think we're saying the same thing. DW has three types of stubs, advertised to be stronger than original. One for the BN1 (and 100S). One for the BN2-BJ7 and the third for the BJ8. As far as I can tell, the only difference between the BN2-BJ7 stub and the BJ8 stub is the machining for the wheel bearings which are different on the BJ8. Again, the caliper mounts which are bolt-on will differ according to the caliper being used.

OK, stand corrected.

 

[Bob_Spidell]

Well, then, I'm still confused. The way I read it is this is the stub axle made for the earlier cars that has brackets to adapt them to a BJ8. But, British is a second language for me.

 

[steveg]

Well, then, I'm still confused. The way I read it is this is the stub axle made for the earlier cars that has brackets to adapt them to a BJ8. But, British is a second language for me.

"...brackets to adapt late BJ8 brakes to an earlier car." would be a better way to describe it.

It's a flexible system that allows replacement stubs which either use one's existing earlier bearings and Type 14 equipment or, using the later stub with a 3.5" bracket allows drum-braked cars to convert directly to late BJ8 Type 16 (or Toyota) equipment. The later stub in combination with 3.5" bracket is a direct replacement for a ruined late BJ8 axle.

 

[Bob_Spidell]

OK, got it. Thanks.

My dad met Norman Nock before he died and they apparently hit it off. Norman was surprised my dad knew the old mechanic's trick of holding the axle at one end and tapping it with a metal tool or bar; if not cracked the axle will ring like a tuning fork but if cracked it'll make a dull 'thud.'

 

[steveg]

OK, got it. Thanks.

My dad met Norman Nock before he died and they apparently hit it off. Norman was surprised my dad knew the old mechanic's trick of holding the axle at one end and tapping it with a metal tool or bar; if not cracked the axle will ring like a tuning fork but if cracked it'll make a dull 'thud.'

Bob - that is a very worthwhile trick!

Assuming the wheel and bearings, etc. have to be removed and the axle clean in order for this to work.
Could you clarify what the "holding" part means?

 

[Bob_Spidell]

Bob - that is a very worthwhile trick!

Assuming the wheel and bearings, etc. have to be removed and the axle clean in order for this to work.
Could you clarify what the "holding" part means?

Balance the (clean, no bearings) axle on a finger at the top or bottom trunnion and tap it with a small ball pein hammer or wrench. Suspending the axle with a wire is probably the best way to do it, so as not to damp the sound any.

To be clear, it's Norman that is no longer with us (unfortunately). My dad's still kicking; he doesn't see too well any more and is almost totally deaf (he can't understand speech unless you shout in his ear, but can still hear a noisy lifter on our BN2 from 20 feet away; go figure).

 

[steveg]

Balance the (clean, no bearings) axle on a finger at the top or bottom trunnion and tap it with a small ball pein hammer or wrench. Suspending the axle with a wire is probably the best way to do it, so as not to damp the sound any.

To be clear, it's Norman that is no longer with us (unfortunately). My dad's still kicking; he doesn't see too well any more and is almost totally deaf (he can't understand speech unless you shout in his ear, but can still hear a noisy lifter on our BN2 from 20 feet away; go figure).

Sorry to keep flogging this, but is the axle entirely removed from the car?

 

[Bob_Spidell]

Sorry to keep flogging this, but is the axle entirely removed from the car?

Yes. It can't resonate if it's installed.

 

[maxwedge5281]

i installed the four piston caliper kit yesterday. basically bolt on with the exception of bending the included hard line to attach the caliper to the flexible line. the calipers are extremely light and very well done.....but......the pad pins would not work! the circllip grooves were about a sixteenth too far apart. i called healey spares and john was very responsive and was to send out new pad pins today! anxious to receive and get on the road!

 

[steveg]

i installed the four piston caliper kit yesterday. basically bolt on with the exception of bending the included hard line to attach the caliper to the flexible line. the calipers are extremely light and very well done.....but......the pad pins would not work! the circllip grooves were about a sixteenth too far apart. i called healey spares and john was very responsive and was to send out new pad pins today! anxious to receive and get on the road!

Can you post a couple of pictures of the calipers as installed? Esp curious about the hard line as it comes off the caliper.

 

[maxwedge5281]

i just talked to healey spares and the pins were shipped today. a couple of pics!

 

[steveg]

I had interference issues with my hard line at full lock. It took me three iterations to get mine correct. See: https://www.pbase.com/stevegerow/healey_discs

You might want to remove the spring and move the suspension up and down at full lock to make sure the hard line isn't hitting the shock tower.

 

[HealeyRick]

Some autocrossing with the Nasty Boy has spurred me into finally doing the front brake upgrade I've been putting off. Here's the plan on the BJ7. Moss, vented, slotted BJ8 discs, Toyota 4 pot calipers following Steve Gerow's install. Because the BJ7 caliper mounts are 3.25" between the ears, I'll be using the Denis Welch mounting brackets that are spaced for the 3.5" ears of the Toyota calipers. I'm planning on following Steve's pattern of the hard lines from the caliper to the mounting bracket to connect to my stainless steel lines. Steve, any tips for me before I jump in?

 

[steveg]

Some autocrossing with the Nasty Boy has spurred me into finally doing the front brake upgrade I've been putting off. Here's the plan on the BJ7. Moss, vented, slotted BJ8 discs, Toyota 4 pot calipers following Steve Gerow's install. Because the BJ7 caliper mounts are 3.25" between the ears, I'll be using the Denis Welch mounting brackets that are spaced for the 3.5" ears of the Toyota calipers. I'm planning on following Steve's pattern of the hard lines from the caliper to the mounting bracket to connect to my stainless steel lines. Steve, any tips for me before I jump in?

This is great news, Rick. It'll be helpful to have the 3.5" DW mounting plate verified in the real world.

More details to the below in my gallery.
Some ideas:
--Moss shows a different PN for the caliper mounting bolts for your earlier-style vs those for the late BJ8 calipers. You'll have to check them out and see if either bolts into the DW plate.`Early '70s TR6 uses a bolt that's 12mm on caliper side and 7/16" on swivel axle side. I used the BJ8 bolts with a tin (steel) can shim wrapped - they've held up without any wear since 2012.
--Moss has a pattern in their online "additional information" section (for the BJ8 Big Brake kit) for opening up the BJ8 dust shield to fit the Toyota caliper.
--I'd buy the Centric posi-quiet loaded calipers on Amazon.
--If your shock tower has the angled corner you may not have to cut away the flange as I did.
--Once you get the hard lines built, with car on stands, strongly suggest removing front springs and moving suspension through full travel at full lock with caliper next to shock tower to make sure nothing hits the brake pipe.
--Toyota uses 10x1.0 metric tube nuts (details on my gallery), but the 3/16" tubing is the same.
--If you use the ceramic pads, probably best to replace the rotors also.
--I now prefer the inexpensive, nearly foolproof Eastwood flaring tool as it appears to make MOPROD universal flares - which should also fit the bubble flare applications in the servos and Jaguar rear calipers if used:

--Eastwood also sells inexpensive inside/outside tubing reamer and tube-straightening pliers.
--Lisle 3/16" tube bending pliers (Amazon) will give you tighter bends than the HF tube bender.
--Federal Hill Trading sells genuine Cunifer tubing - recommended.

I bought a $12 roll of OEM-style steel tubing from Eastwood (IIRC) to practice with before making the finals with Cunifer.

 

[steveg]

Balance the (clean, no bearings) axle on a finger at the top or bottom trunnion and tap it with a small ball pein hammer or wrench. Suspending the axle with a wire is probably the best way to do it, so as not to damp the sound any.

To be clear, it's Norman that is no longer with us (unfortunately). My dad's still kicking; he doesn't see too well any more and is almost totally deaf (he can't understand speech unless you shout in his ear, but can still hear a noisy lifter on our BN2 from 20 feet away; go figure).

I confirmed this today, removed the nut, washer and spacer from my two old axles (each hung from a loop of wire) and tapped with small ball pein hammer - nice, xylophone-like tone on both! With washer, nut and spacer, a dull tap is all.

Bob - thanks again for passing along this tip!
PS - the response was old enough the "Thanks" button was not showing.

 

[John Turney]

We need someone in the UK to call DW and find out if their 3.5" bracket will fit on the pre-BJ8 style stub axle. All DW's site says is it works in conjunction with their replacement stub axle.

I have the DW bracket with Girling Type 16s, 3/8" discs and my original BN4 stub axle.