Air Seal (MM33108 & MM33122)
MM2709
Hydromaster & Hydrovac · Catalogue page 82
Product details
Outside Diameter = 244 Inside Diameter = 188 Height = 18 1 Per KIT
All products
Hydromaster & Hydrovac repair kits
Hydromaster and Hydrovac booster repair kits and air seals.
7 product lines · ManuMark 2026 catalogue
Fitting notice: Air brake components must be fitted by a qualified technician and matched to your vehicle’s exact part number.
7 products
HYDROVAC #9320-1374
MM33108
Hydromaster & Hydrovac · Catalogue page 82
Product details
Main Shaft 8mm 10mm For Air Seal see MM2709 Includes O-Rings & Seals
HYDROVAC (Extra Long)
MM33108/1
Hydromaster & Hydrovac · Catalogue page 82
Refer to our sales team for compatibility details.
HYDROVAC #9320-1379
MM33109
Hydromaster & Hydrovac · Catalogue page 82
Product details
Main Shaft 8mm Seal Outside Diameter = 175 Inside Diameter = 119 Height = 18
JIDOSHAKIKI
MM33109/1
Hydromaster & Hydrovac · Catalogue page 83
Product details
Outside Diameter = 175 Inside Diameter = 119 Height = 18
BENDIX
MM33122
Hydromaster & Hydrovac · Catalogue page 83
Product details
KIT No. 9320-1206 Main Shaft 8mm For Air Seal see MM2709 Includes O-Rings & Seals
CLAYTON DEWANDRE
MM33143
Hydromaster & Hydrovac · Catalogue page 83
Product details
KIT No. 700 749 701 653 701 662/3 Main Shaft 8mm 701 290 701 659 Original has leather main seal 070 829 970 1662 Small U-Seal
About hydromaster and hydrovac repair kits
Hydromaster and Hydrovac units are vacuum-assisted hydraulic boosters used on light and medium trucks and buses.
When to replace
Loss of brake assistance, a hard pedal or fluid being drawn into the vacuum side indicate worn seals or a torn diaphragm.
What's in the kit
Kits contain the diaphragm, piston cups, seals and control valve rubbers for the units in this range. All 7 hydromaster & hydrovac lines are manufactured by Pitchline Engineering in an ISO 9001 environment in Pinetown and supplied from our Pinetown branch across South Africa.
Hydromaster & Hydrovac questions
What is the difference between a Hydrovac and an airmaster?
A Hydrovac uses vacuum to boost hydraulic pressure; an airmaster uses compressed air.
Can a Hydromaster be rebuilt?
Yes, if the cylinder bore is good. A repair kit restores the diaphragm and seals.
How many Hydromaster and Hydrovac kits do you stock?
All current part numbers are listed on this page from the 2026 catalogue.