Reconditioning Accumulator Valve Bodies Part 3 : Testing
Welcome to another detailed guide for Rolls-Royce and Bentley enthusiasts, where we focus on the testing process of Accumulator Valve Bodies for models running RR363 brake fluid. As these valve bodies are no longer available directly from the factory, reconditioning is the only available option for these key components.
In this video linked here, we explore a step-by-step process demonstrated by our in-house expert, Matt Duncan, who shows us how to test two accumulator valve bodies (Early model: UE37583SXR, Late model: UE39519XR) applicable for Rolls-Royce Silver Shadow I, Rolls-Royce Silver Shadow II, Bentley T1, and Bentley T2 models. This is part 3 of a 3 part video tutorial.
Testing Accumulator Valve Bodies: A Must-know for Rolls-Royce and Bentley Owners
The testing process requires supplying high pressure to the feed port on the top of the Valve Body. This process is conducted using a machine essentially composed of an electric motor that turns a shaft with a bearing to activate the push rod and, subsequently, the brake pump. This mechanism allows for the efficient measurement of the brake pumps' effectiveness and their working condition.
Matt demonstrates how to connect and pressurize the Valve Bodies, which are attached to a sphere and an accumulator for the test. He takes us through the role of the sphere, which is charged with 1,000 PSI of nitrogen to provide a reserve of pressure for the braking system.
The test focuses on the pressure readings and their implications. Matt explains how a healthy Valve Body should behave during the test: it should flick up to 1000 PSI (the sphere pressure), then the pump will slowly produce pressure up to about 2500 PSI before stopping and then returning through the return line. The expected pressure to hold should be around 2400 or 2350 PSI.
The video also covers potential issues that might arise during the testing and how to troubleshoot them, such as needing to prime the brake pump due to running low on fluid. Matt emphasizes the importance of understanding these scenarios, as they can similarly occur when working on the actual car.
Lastly, Matt talks about the "cracking off" of pressure - the point at which pressure buildup in the system stops and pressure returns back to the reservoir. He also provides valuable insight into the reserve pressure system, indicating how the diaphragm in the sphere uses banked up gas pressure for the brakes.
In the end, successful reconditioning leads to a Valve Body that cracks off at 2500 PSI and holds pressure at 2300 PSI, thereby making the unit ready for use.
Accumulator Valve Bodies: Buy Reconditioned
The two Accumulator Valve Bodies shown in this video are available as reconditioned exchange units. If you wish to purchase a unit directly, use the following links.
Accumulator Valve Body UE37583SXR
- Rolls-Royce Silver Shadow I (RHD 1001-26708, LHD 1001-20753)
- Bentley T1 (RHD 1001-26708, LHD 1001-20753)
Accumulator Valve Body UE39519XR
- Rolls-Royce Silver Shadow II (RHD 30001-41686, LHD 20755-41686)
- Bentley T2 (RHD 30001-41686, LHD 20755-41686)
1 June 2023