Brakes & Hydro Boost

Due to the increase in power from the Cummins engine and my desire to hold the truck on steep inclines I have bought a conversion kit designed by Timm Cooper that will allow me to use stock, unmodified land rover break components. The kit will be available from Forbyn Brothers in the very near feature. Keep your ear to the ground and snap up a set as soon as they come on the market.
The kit is made of very high quality parts made in the USA.

I bought used Defender 110 front calipers. I cleaned them and rebuilt them using stainless steel pistons from Rovers Down South. I bought used Discovery S1 rear calipers.

I painted the calipers with high heat paint. Other people have powder coated the calipers with mixed results. A proper powder coating job would be the best way to do it but The spray paint job will do just fine.
My Land Rover originally came with a single cylinder non assisted master for the brakes! This will not work with Disc brake of any sort.
Late 2a and Series 3 Land Rovers came with vacuum assist power brakes. Using the tower and parts form a S3 is a good idea if you are using a gas engine or have a vacuum pump. I will have neither so I am using a hydroboost master cylinder. It can be diffuilt to fit this large unit under a Series Land Rover’s hood. Ike Goss made it to easy for me by building a sweet bell crank break tower that moves the master cylinder inboard far enough to clear the hood.

Adding power steering made a hydraulic pump necessary. Using a hydro boost master cylinder will only require a little more plumbing. I will not have to fuss with a vacuum pump.

This combination will provide plenty of stopping power.


For plumbing I took Timm Cooper’s advice and laid out the plumbing in the style of an early Bronco.
Brake Bill of Materials.
2) 10mm straight narrow banjo x -3AN flex line 12″ overall length. Runs from front calipers to the axle hard line. Sourced from Pacific Rubber Seattle Wa



2) 3/8-24 inverted flair Tee with mounting hole.
To connect the front and rear axle hard lines to the flex lines running to the frame. sourced from Jegs

2) -3AN x -3AN flex line 20″ overall.
To run from the axle Tee to the frame hard lines. Sourced from Pacific Rubber Seattle Wa

1) 10 Pack 3/8-24 inverted flair fittings.

To connect the axle hard lines to the Tee’s. Sourced from Jegs

1) 10 pack 10mm banjo copper washers. Sourced from Jegs

2) 3AN male x 3/8-25 inverted flair fittings. To connect the flex lines to the Tee’s. Included with the Tee’s or available separately from Jegs

2) 25ft Rolls break line

1) Hydroboost form a 1985 Chevy 1ton diesel pick up

1)Master Cylinder from a 1985 Chevy 1ton diesel pick up

1) Set Land Rover Defender 110 front Calipers

1) Set Land Rover Discovery 1 rear calipers

1) Set front and rear Disk Brake conversion castings from Timm Cooper. Soon to be available from Forbyn Brothers.

1) Set Vented Land Rover 110 front disk’s

1) Set non vented Land Rover Discovery 1 rear disks

Power steering pump and hydraulic plumbing will be detailed on the Power Steering page.

3 Responses to Brakes & Hydro Boost

  1. Steve says:


    Hope you don’t mind a question on the Hydroboost setup. I also have a Series 2A , with Defender discs on all 4 corners (older Timm Cooper kit from Rovers North) and S3 tower. The electric vacuum pump and Defender brake booster combo is not working – suspect is a bad booster. Since I am doing the power steering apconversion as well, I saw that I can buy a PS pump with 2 sets of ports exactly for both PS and Hydroboost.

    Did you install the Chevy 1-ton Hydroboost and MC as you listed above? Does the setup work? Do you remember the part numbers? (Probably Hydratech can figure it out so no big deal.).

    Did the bolt holes on the tower align to the ones on the Hydroboost?

    Was the rod from the Hydroboost to the tower able to be adjusted without surgery?

    Any lessons learned?

    Thanks in advance, really appreciate it!

    Best regards,


  2. admin says:

    I did. I do not have part numbers available right now. I can look them up. I have not competed the instalation yet so I do not know how well it works personally. This is the way Timm, Ike, and several others suggest so I think it will work well. The Hydroboost has to mount inboard of the tower to clear the hood. A bell crank is needed. Ike Goss at Pangolin 4×4 modified my tower and did a very nice job. his website is

  3. Alojamiento says:

    To check the vacuum booster, pump the brake pedal with the engine off until you’ve bled off all the vacuum from the unit. Then hold the pedal down and start the engine. You should feel the pedal depress slightly as engine vacuum enters the booster and pulls on the diaphragm. No change? Then check the vacuum hose connection and engine vacuum. If okay, the problem is in the booster and the booster needs to be replaced.

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