This document details experiences and insights from users installing a Davies Craig 678 transmission oil cooler, focusing on thermal switch options and installation considerations on a Toyota Prado.
Problem
Users are looking for guidance on selecting and installing a suitable thermal switch for use with the Davies Craig 678 transmission oil cooler. Another user encountered an air conditioning pipe obstruction when transferring a cooler from an older model Prado to a newer one.
Solution
- Thermal Switch:
- One user reported using a Derale thermal switch sourced from eBay, installed between the cooler inlet and outlet. This thermostatic switch is designed to allow approximately 5% flow when closed to prevent hammering or air locks. It opens at approximately 80 degrees Celsius, allowing full flow to the cooler when the transmission fluid reaches that temperature. The purpose of the switch is to facilitate quicker transmission warm-up in colder months.
- Another user reported not using a thermal switch at all, even in hot climates (40+ degrees Celsius), without any issues.
- Air Conditioning Pipe Obstruction:
- When transferring the cooler from a 2010 model to a 2017 model, an air conditioning pipe obstructed the original mounting position. The solution was to insert a 3-inch spacer at the base of the transmission cooler and keep the top brackets under the horn mounts. This resulted in an angled cooler installation.
Relevant Parts
- Transmission Cooler: Davies Craig 678
- Thermal Switch (Optional): Derale thermal switch (sourced from eBay)
- Spacers: 3-inch spacer (used for installation on 2017 model due to AC pipe obstruction)
This technical summary was auto-generated based on recovered archives. Do not rely on its factual accuracy. Refer to the original thread. Source: View Original Conversation
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