Signs of failure in Vacuum Modulator

The vacuum modulator is an automatic transmission component whose purpose is to help the engine work properly in order that speed changes can be made smoothly. The vacuum modulator puts pressure on the car's accelerator valve by pressing the pedal, helping to respond to the engine's load demand.

With the above process the car´s automatic transmission can change the speeds correctly if the engine maintains an adequate vacuum load level.

If the transmission's vacuum modulator begins to fail when changing gears, the hose that attaches the engine vacuum to the transmission can burn out and cause engine damage.

When the vehicle goes downhill it experiences a low engine load, and the opposite happens when driving uphill, with a heavy load on the engine. If the modulator is failing, it could end up changing gears in reverse.

The transmission valve body helps control the vehicle's direction changes, transmitting the fluids needed for an optimal gear change. The vacuum modulator calculates the load on the car engine with the diaphragm; when a gear change is executed in line with the load demand, the diaphragm pushes the valve so that the spring moves in the reverse direction to the diaphragm.

With these components working properly, the transmission will work properly as well and there will be no damage to the vacuum modulator. However, if there is a failure, there could be an inability or difficulties with the automatic transmission to change markings properly.

If the vacuum modulator is perforated or leaking, it can cause the engine to absorb the transmission oil through the valve, and in this case, the oil entering the engine is transferred to the combustion chamber, where it burns and causes breakdowns, in addition to an expulsion of smoke by the exhaust.

When the automatic transmission fails, it is usual to check the oil level, gears and electrical problems. However, in routine check-ups it is also important to check the vacuum valves and modulators condition, which can cause problems similar to other components failures.

Take your vehicle with a specialized mechanic and be sure to purchase high-quality tools and spare parts to replace the damaged ones. In the Sun Transmissions online store you will find a wide variety of products that you can buy and receive at home, like the power steering rebuild kits, automatic transmission cooler, automatic transmission additives, transmission bushing kits, automatic transmission filters, and all for your rebuilding needs. For more information write to us through our contact form or to support@suntransmissions.com where we will gladly solve all your questions.