Rimmer's helped me determine Rear brake cylinder bore sizes
Posted: Sat Aug 15, 2015 7:51 pm
I have for a long time believed that up until the dual braking system was introduced on 1500 & 1850 dolomites that the rear brake cylinders were 3/4 inch and that when the dual system was introduced the rear cylinders were changed to 5/8 inch. I now know that this is NOT the case as up until the dual system was fitted the rear brake cylinders were actually only 0.7 inch.
Rimmers very quickly provided a response, which included an extract from a Lockheed publication, when I queried the fact that they had provided me with a pair of 0.7 dia brake cylinders when I was expecting 3/4 dia.
For info 1300 and Sprint have always been fitted with 0.7 inch diameter cylinders.
On checking some old cylinders which I have removed over the years the majority were 0.7 inch dia but I did have one pair that were 3/4 dia so if you are planning to replace complete cylinders or just to fit new seals I recommend you check the bore size. If you fit the larger 0.7 inch or 3/4 inch bore in a dual system I believe the master cylinder can not provide sufficient hydraulic fluid if there is a leak in one half of the system.
Rimmers very quickly provided a response, which included an extract from a Lockheed publication, when I queried the fact that they had provided me with a pair of 0.7 dia brake cylinders when I was expecting 3/4 dia.
For info 1300 and Sprint have always been fitted with 0.7 inch diameter cylinders.
On checking some old cylinders which I have removed over the years the majority were 0.7 inch dia but I did have one pair that were 3/4 dia so if you are planning to replace complete cylinders or just to fit new seals I recommend you check the bore size. If you fit the larger 0.7 inch or 3/4 inch bore in a dual system I believe the master cylinder can not provide sufficient hydraulic fluid if there is a leak in one half of the system.