The purpose of this page is to help you choose the booster most suited to your needs

Most of the Girling, Lockheed, Bonaldi and other British and European types of hydraulic boosters were made to suit a particular vehicle ,but this does not mean a PBR or other type of booster cannot be substituted if, for one reason or another the original booster cannot be repaired.  

VH 40s and 44s can be made in a multitude of outputs and mounting configurations to replicate virtually any original equipment booster installation as well as being able to be configured to suit all types of original applications.

When choosing a booster for your car we need to know what type of foundation brakes you are using  ie. whether you're using drums or discs, what size are your brakes, are you running a single or a split hydraulic system ,how much room do you have, are you going to mount the booster under the front guard,, or maybe in the boot or under  the bonnet? All these facts need to be considered when choosing a booster for  your car.

If you are using a dual hydraulic system in most cases you will need to run two hydraulic boosters, one for the front and one for the rear or in some cases if the balance of the front and rear is suitable you can boost the front only. Obviously a mastervac or mechanical booster is more suited to a dual hydraulic setup for many reasons, so room permitting, this is the way to go.

Mastervacs like VH40s and 44s come in all shapes and outputs so it is quite likely that Terry can supply one to suit your requirements off the shelf or we can custom modify an existing one to suit your particular application. Mastervacs vary in size from the Gemini which is 7" in diameter and popular with the Hotrod fans for underfloor applications up to the tandem 9" and 11" models and plenty in between.  HYDROBOOST  have had years of experience in booster to car matching so give Terry a ring and he'll put you on the right track.

       We have a large range of mounting brackets both reproduction and replated original to suit all types of vehicles . We can also supply remote air cleaner adaptors for under guard VH44&40 fitment.

Big Bore VT Commodore and BA Falcon  calipers are becoming more popular with car builders and with these calipers the problem of excessive pedal travel can occur. With this in mind Hydroboost has developed an adaptor which allows a Commodore fastfill mastercylinder to be fitted to most early model PBR mastervacs . This adaptor allows you to use the master cylinder designed for these calipers therefore eliminating the low pedal problem

    Commmodore fastfill mastercylinder adaptor.                    

                          BOOSTER IDENTIFICATION                        

                PBR mastervacs all have VH----- numbers stamped on them (see photo) Some vehicles like Ford F Series have various types fitted so a part number is a big help when making enquiries.

                   HQ- HJ - HX -HZ Holdens fitted with 11" single diaphragm mastervacs have three different input shafts ( see photos ) so if you need a changeover a description of the type of input shaft will ensure you get the correct replacement. The picture on the left shows a fixed yoke input shaft, the middle picture is an adjustable yoke and the picture on the right is the flat type which is used when the brake pedal has a peg rather than a hole for the pushrod to attach. Some of the very late model 11" mastervacs are fitted with the plastic reservoir type master cylinders and these have a diagonal bolt pattern whereas all the others have a horizontal bolt pattern and we need you to tell us all these variables so that we can supply the correct changeover unit for you.

VH 40 and VH 44 can be made up in either right or left hand configuration .How you determine the right or left is to look at the front of the booster an see whether the mounting bolts are on the right or left hand of the valve body.The photo shows a right hand mount. Also to help you determine what will  fit,  the VH 40 is 91/2" or 230mm in length and so is the VH44 but the VH 40 is 93/4" or 240mm in diameter whilst the VH 44 is 71/2 " or 190mm.The input and output hydraulic ports are 3/8" UNF and will accept 3/16"tube with a P4285 tube nut without adaptors. adaptors are available from HYDROBOOST to suit 1/4" tube. 

Unfortunately with most VH40 and 44s unless they were fitted as standard equipment there is often no way to identify the model as most of them don't have the original identification tags so we will often ask you to send your old booster for us to dismantle so that we can supply the correct changeover unit.

We can modify mastervacs in many ways to suit your vehicle if you can't get by with a standard unit. We can change the mounting studs front or rear or both. We can change the input shaft, the output pushrod the valve setting,  the reaction feel, in other words nearly everything can be altered and we don't charge the earth for modifications                                                                             



Over the years many people have sent boosters to us that they had purchased from garage sales, swap meets or online auction sites that were supposedly recently reconditioned done no work or were in perfect working order  only to find out on inspection that they were completely seized or leaking like a sieve and required complete overhaul  before they could use them, and to add insult to injury they often paid far too much for supposedly hard to get boosters ,so please if you buy a second hand  booster ask the  seller if they will give any guarantee on the working condition of the booster or better still, give Terry a call at HYDROBOOST because as well as repairing customers boosters and providing changeover units Terry can in most cases sell you a fully guaranteed power brake without you providing a trade- in unit, and at a price that will please you.


Don't forget, if you have any enquiries the best way is to ring either Terry and have a chat . Terry looks forward to doing business with you.


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