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R35 GTR servo and master cylinder conversion


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Was unable to find one a good booster for my R32 so thought I’ll try and do an R35 conversion. 

First drive with it there and brake feel and stopping power is incredible. 

The bolt pattern for the servo at the bulkhead is identical so no drilling needed. However bolt pattern and angle of mounting for the master cylinders are different so you’ll have to use a 35 cylinder. 

The “U” the clevis pin goes through is shorter on the 35 but can be swapped over for your original one as they’re the same thread. 

You’ll need some male to male fittings for standard brake lines to extend round as the fittings for the brake lines are on the other side for the 35 unit, you’ll need fittings for the cylinder (I think 7/16th, I’ll be honest I handed the parts guy the cylinder and said get me something that fits that) I’ll likely redo these with braided lines and banjo bolts in future.

Finally you’ll need some 10mm fuel hose to connect the vacuum reservoir to the booster as the fitting is on the other side 

 

8BF45F9D-3030-4FDD-8EB8-5BC68DE0B295.thumb.jpeg.e6dad53712116ad2e50fec5e46ce15d8.jpegFAE0F58E-0533-4D1B-88BE-7F9E95644E70.thumb.jpeg.1507f09969a65d8c373feb2382921666.jpeg93AB6ADF-7C09-40E2-A636-2F8BDF79A60F.thumb.jpeg.df407ae4285419a9ea10d155e56d4b54.jpeg

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I am pretty sure if you use one from a LHD r35 the ports are on right side vs on the left side for a RHD. Going by the service data the R35 uses a 1 1/8th master cylinder vs the R33/34 GTR BM57 1 1/16, so less pedal travel but more effort. I wonder how much of a difference there is in the booster diaphragm diameter. The R35 service manual says Primary: 230mm (9.06) Secondary: 205mm (8.07) does anyone have the service data for a R32-34 gtr booster?

Edited by Josh222
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I'm not shitting on the approach of retrofitting something from a newer car - I've done plenty of it myself.

But I do have to wonder why no-one ever goes to the effort of getting their failed booster reconditioned? It's easy. Just go to your local expert brake company (ie, ABS in Adelaide) and hand it over with $200 or so.

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I guess the R32 reservoir didn't fit on the R35 cylinder?  That would have saved the trouble to rewire fluid level sensor.  

And yes the LHD cylinder has ports on other side, so no fitting would be needed.

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  • 10 months later...
On 17/04/2022 at 12:53 AM, McGarryR32 said:

Was unable to find one a good booster for my R32 so thought I’ll try and do an R35 conversion. 

First drive with it there and brake feel and stopping power is incredible. 

The bolt pattern for the servo at the bulkhead is identical so no drilling needed. However bolt pattern and angle of mounting for the master cylinders are different so you’ll have to use a 35 cylinder. 

The “U” the clevis pin goes through is shorter on the 35 but can be swapped over for your original one as they’re the same thread. 

You’ll need some male to male fittings for standard brake lines to extend round as the fittings for the brake lines are on the other side for the 35 unit, you’ll need fittings for the cylinder (I think 7/16th, I’ll be honest I handed the parts guy the cylinder and said get me something that fits that) I’ll likely redo these with braided lines and banjo bolts in future.

Finally you’ll need some 10mm fuel hose to connect the vacuum reservoir to the booster as the fitting is on the other side 

 

8BF45F9D-3030-4FDD-8EB8-5BC68DE0B295.thumb.jpeg.e6dad53712116ad2e50fec5e46ce15d8.jpegFAE0F58E-0533-4D1B-88BE-7F9E95644E70.thumb.jpeg.1507f09969a65d8c373feb2382921666.jpeg93AB6ADF-7C09-40E2-A636-2F8BDF79A60F.thumb.jpeg.df407ae4285419a9ea10d155e56d4b54.jpeg

I have purchased everything - Booster, BMC, 10mm Hoses - only thing i would need your help with is the wiring - do you think you can share some images? 

I also got some Steel Braided hoses for the BMC to the original lines - hope they work! Will upadte here when i start the process of getting it in. I attached pic here

I have a 6 pot 4 pot set up - and the BMC50 - i think is insufficient - i lost brakes at the track yesterday - leg went all the way down on first lap - was very spongy on high rpm but nice and firm driving normally - i reckon is the booster or one of the lines - so i decided to change everything to do with the BMC, Booster, Vacuum hoses. And i totally get why you did this mod - i find i makes perfect sense - especially when its almost plug and play.

 

 

 

Screenshot 2023-02-24 at 8.09.35 pm.png

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On 25/02/2023 at 7:14 AM, Dose Pipe Sutututu said:

Still running ABS? If so is it shielded from the turbo/dump/gate, etc.?

 

Yep still running ABS - also still running twins - never happened before in so many track days - the only difference is the 6 pot 4 pot upgrade - i reckon its the servo dying as well - lets see

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Regards wiring for the fluid level I’ll be honest I didn’t bother with it. It was checked for leaks then I just keep an eye on the level hasn’t budged in a year.
I’m sure a plug could be got that would fit and then it’s only a couple wires if you really wanted.

Also get a heat shield around your ABS unit, I made one up out of some aluminium and helped a lot. 

 

 

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  • 2 weeks later...

Coming along rather nicely - so i will document a bit here to assist this post. (All Prices in AUD)

Hopefully the hoses are long enough - looks long enough... 

On the R35 BM size - confirmed size = 7/16 - and for the R32 Side = 3/8

Will attempt it soon when my Brake Fluid arrives

Cost so far:

Brake Master - $189

Brake Booster - $149

HEL Custom Lines (made a mistake here - should have gotten the Left Fitting as a Male 7/16 - then i would not need the adapter below) - $120

Left Fitting -Swivel Male
Left Fitting Size - 7/16" x 20 UNF (-4 AN JIC) 
Left Fitting Angle - 90°
 
Right Fitting - Swivel Female
Right Fitting Size - 3/8" x 24 UNF (-3 AN JIC)
Right Fitting Angle - 45°
Length - 20cm

3M of 10mm Silicone Hoses - $34

Aluminium One Way Valve - $13.50

Brake Tube Adapter - Male 7/16 NS, Female 3/8 (this is unnecessary cost - i made a mistake when i ordered the HEL lines) - $34.70

332374899_1205279790381924_670552316546493035_n.thumb.jpg.3df43e0d9947e82f2fbf5e1b7388c594.jpg332808026_176364501812714_5217128666932624682_n(1).thumb.jpg.a865451620218319b869fa0158ab0b53.jpg333003612_3521060741511220_8274232529391343397_n.thumb.jpg.f7e7a4c702bc46e6b15e5bdc2d72624b.jpg335016031_625456392729126_3720102994372258975_n.thumb.jpg.aa53c1894983aa923436d765011f15fe.jpg

I rounded the nut on the master for the old R32 brake line - it was completely seized - so i decided to custom 2 lines from Master to the ABS unit.

Front Master Port - $75.00
Left Fitting - Fixed Male 
Left Fitting Size - 3/8 x 24 UNF (-3 AN JIC) 
Left Fitting Angle - Straight 
Right Fitting - Swivel Male 
Right Fitting Size - 3/8 x 24 UNF (-3 AN JIC) 
Right Fitting Angle - 70° 
Length - 97cm - extra 1cm

Rear Master port - $75.00

Left Fitting - Fixed Male 
Left Fitting Size - 3/8 x 24 UNF (-3 AN JIC) 
Left Fitting Angle - Straight 
Right Fitting - Swivel Male 
Right Fitting Size - 3/8 x 24 UNF (-3 AN JIC) 
Right Fitting Angle - 70° 
Length - 91cm - extra 1cm

This is how the line will roughly look like:

image.png.1cc5aead44a126d743dc6b18386401e9.pngimage.thumb.png.d3f69b5fc8fa1cdcc0deaa21384a5cc0.png

This is how i plan to run it - please use imagination a bit - i will take more pictures once its installed. But the 2 lines will run across the firewall similar to the original hard lines.

image.thumb.png.98cf00f91cd063b61fef258f541d64d6.png

Confirmed the Plug is the same as BM57 - its quite hard to get the plug - it is shared with a LOT of different cars - R35, Pathfinder, G35, Subaru WRX, Ford Fiesta - but its almost impossible to buy one - and 100% impossible to get in Au

I found the details in the thread below - have to thanks to @BK for ALL the research he did - especially in where to purchase. MOTORCRAFT WPT-1385 is the part number - meant for Ford.

image.png.2a2690ba78283fffa51e12a57d7565b6.pngimage.thumb.png.6ff14ba2611ccca68b65539af8c105c1.png

image.thumb.png.0dccd5762504231161386691c00bb6d4.png

 

Edited by deongster
Updates - This is Main Journey
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  • 3 months later...
1 hour ago, deongster said:

i just would like to say - i have been searching all over the world - literally to find the bloody fluid level connector - no one seems to sell a R35 GTR connector hahahaha

image.thumb.png.ff680c8f2876a1d9fedcf8351c405f35.png

Another thing - i rounded the nut on the master for the old R32 brake line - it was completely seized - so i decided to custom 2 lines from Master to the ABS unit.

Front Master port = 96cm (extra a cm in case)

Rear Master port = 91 cm (Extra cm in case)

This is how the line will look like:

image.thumb.png.d3f69b5fc8fa1cdcc0deaa21384a5cc0.png

This is how i plan to run it - can use imagination a bit - i will take more pictures once its installed. But the 2 lines will run across the firewall similar to the original hard lines.

image.thumb.png.98cf00f91cd063b61fef258f541d64d6.png

I’m pretty sure that plug is the same as the r33 which is also used by subaru and some ford models, I can double check when I get home tomorrow 

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On 17/04/2022 at 12:53 AM, McGarryR32 said:

Was unable to find one a good booster for my R32 so thought I’ll try and do an R35 conversion. 

First drive with it there and brake feel and stopping power is incredible. 

The bolt pattern for the servo at the bulkhead is identical so no drilling needed. However bolt pattern and angle of mounting for the master cylinders are different so you’ll have to use a 35 cylinder. 

The “U” the clevis pin goes through is shorter on the 35 but can be swapped over for your original one as they’re the same thread. 

You’ll need some male to male fittings for standard brake lines to extend round as the fittings for the brake lines are on the other side for the 35 unit, you’ll need fittings for the cylinder (I think 7/16th, I’ll be honest I handed the parts guy the cylinder and said get me something that fits that) I’ll likely redo these with braided lines and banjo bolts in future.

Finally you’ll need some 10mm fuel hose to connect the vacuum reservoir to the booster as the fitting is on the other side 

 

8BF45F9D-3030-4FDD-8EB8-5BC68DE0B295.thumb.jpeg.e6dad53712116ad2e50fec5e46ce15d8.jpegFAE0F58E-0533-4D1B-88BE-7F9E95644E70.thumb.jpeg.1507f09969a65d8c373feb2382921666.jpeg93AB6ADF-7C09-40E2-A636-2F8BDF79A60F.thumb.jpeg.df407ae4285419a9ea10d155e56d4b54.jpeg

hey mate have a question - do you use the R35 aluminium spacer? from your pics it doesnt look like you do but jsut need confirmation

 

image.thumb.png.aa499c49e32a9725f19b702a48cf14f9.png

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4 hours ago, deongster said:

hey mate have a question - do you use the R35 aluminium spacer? from your pics it doesnt look like you do but jsut need confirmation

 

image.thumb.png.aa499c49e32a9725f19b702a48cf14f9.png

I know you also commented on my post, but you didn't post this picture there. I don't use that spacer, just put a paper gasket between the booster and the firewall and you're good to go!

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