Au 2 booster in AU 1

EF_Ghia · 18-05-2011, 08:46 PM

Hi guys, had a good search around cant seem to find any info on this. I tried fitting an Au 2 booster into an AU 1 which I have fitted AU 2 brakes on. I drilled the extra holes to mount onto firewall and bolted it in, but the brakes stick on for a moment after pedal is released.

Has anyone else tried before? Im thinking the firewall is moulded different and the booster cant be mounted flush, or possibly there is more vacuum pressure on the series 2/3?

superroo · 19-05-2011, 03:16 PM

I'm not sure what your problem is, but I’m running a BF booster and master in my au1. I have some pedal feel problem, but they are unrelated to the booster/master change (existed before the change).

What master you running?

Cheers

**Papa Smurf** · 19-05-2011, 06:30 PM

EF Ghia, did you make sure the booster lined up properly before you drilled the holes? Sounds like the shaft from the booster is grabbing against the firewall or the Dash Bracket.

I am about to add a AUII booster to my AUI XR6, I am also changing the bracket from under the dash as I really don't feel good about having 6 holes in the bracket.
I will be using an AUII Tickford T series M/Cyl with the later booster. I have BA fronts and am putting BA rears on and I hope it all works ok.

Davo3460 · 19-05-2011, 10:07 PM

you will need to adjust the pushrod from the pedal to the booster

EF_Ghia · 20-05-2011, 08:46 AM

Hey, thanks for your help guys!

superoo: I have an AU3 booster which I was using as it had the same length pushrod as the au1, but also have a BA booster which I also tried however the length of the pushrod is so long that the brake pedal sticks out so far. Is there an adjustment?

papa smurf: I dont think I had it lined up perfectly center, so it was probably grabbing on the firewal as you suggest.. You mentioned changing the bracket, I didnt realise there was a bracket? That would be a much better idea than drilling the existing bracket, is it simple enough to remove/replace? I will have to find myself an AU11 bracket.

davo3460: how do you adjust?

superroo · 20-05-2011, 01:34 PM

Quote:

Originally Posted by EF_Ghia

superroo: I have an AU3 booster which I was using as it had the same length pushrod as the au1, but also have a BA booster which I also tried however the length of the pushrod is so long that the brake pedal sticks out so far. Is there an adjustment?

With a hack saw, grinder and welder anything can be adjusted

Also, the pedal end of the boosters is different and as such a shortened BF (and i would guess BA) doesn't activate the brake light switch properly. An AU end is needed.

Cheers

EF_Ghia · 20-05-2011, 02:23 PM

haha I see, so you cut the ends of AU 1 booster and BF booster and welded the AU1 pushrod onto the BF pushrod at the correct length?

I think the issue I must be having with the pedal sticking momentarily after I apply the brake, must be the pushrod touching on the firewall and I dont think I managed to get it quite centred.

**Papa Smurf** · 20-05-2011, 05:47 PM

EF Ghia, if you get yourself off to a wreckers you should be able to pick one up cheap, not many people buy them.

Boza · 22-05-2011, 02:05 AM

Im collecting bits for an au2 brake conversion on my au 1 I thought you don't have to change booster/mastercylinder or am i missing something here.

also got told if i go to au2 mastercylinder that my cruise won't work

**Papa Smurf** · 22-05-2011, 04:54 AM

Well, you don't HAVE to change the booster and M/Cyl as I am running the AUI type now but the series II/III works better as the M/cyl has a different internal diameter and works more efficiently.
I don't know who told you that the cruise wouldn't work as the switch in the M/cyl is the same for all AU's.

Boza · 22-05-2011, 11:30 AM

Papa Smurf did you have to adjust your booster pushrod much after you converted the brakes.

**Papa Smurf** · 22-05-2011, 07:21 PM

I didn't change anything. There is no adjustment on the pushrod that joins the brake pedal but there is a slight adjustment on the rod that goes into the back of the M/cyl but I wouldn't suggest you touch it.

The best thing to do is to change the booster and M/cyl and use one from an AUII/III, the M/cyl on AUII/III has a larger internal diameter.

Boza · 22-05-2011, 08:30 PM

Quote:

Originally Posted by Papa Smurf

I didn't change anything. There is no adjustment on the pushrod that joins the brake pedal but there is a slight adjustment on the rod that goes into the back of the M/cyl but I wouldn't suggest you touch it.

The best thing to do is to change the booster and M/cyl and use one from an AUII/III, the M/cyl on AUII/III has a larger internal diameter.

yeah thats what i'm most likely gonna do a workshop is gonna do mine so do i just change the booster bracket from under the dash or do I still tell them to drill

**Papa Smurf** · 22-05-2011, 10:28 PM

Matey, I would get the NEW bracket and change it. If you use the old one you would be drilling another 4 holes that would make 6.
I guess you could keep the bracket but personally, I am going to change it.

Boza · 23-05-2011, 02:10 PM

With the bracket does the dash have to come out or can you get away with pulling it out from behind the dash just gotta tell the bloke at the shop but he is meant to be a break specialist so I can't see him having any problems.

robertjp · 17-04-2012, 11:58 PM

sorry to drag up and oldish thread, but what bolts hold this bracket on and has anyone had problems were the brakes dont release until they lock solid? Can anyone please help?

robert

robertjp · 22-04-2012, 05:11 PM

Papa smurf did you ever change the steel mounting plate for the brakes, steering etc. It looks like a complete pain but how hard was it to do.

Robert

falcon AU S · 28-04-2012, 12:12 PM

I have taken out the steel mounting plate for the brake pedals from an au3 it wasn't hard all you need is a 13mm deep socket and some patience, and no you don't need to take out the dash you can do it from under it.
The problem that I am stuck with now is that I got a 5 speed box in my au s and they have a different mounting plate incorporating the clutch pedal ....
Any suggestions?