Majority of the transmission system failures I have come across from my years of practice in the automotive field, has always being related to either the transmission system throwing up codes in the ECU or its TCM(depending how yours was designed), or some of the solenoid actuators actually going bad.
If you’re a car enthusiast, and suddenly get some sort of JERK FEELINGS, or the transmission system acting up as though it was in NEUTRAL, what would you do?
Let’s even assumed you got one of the cheap OBD2 code readers around.
The first thing that might come to your mind might be, GETTING ANOTHER TRANSMISSION SYSTEM. But that’s what dome shops might recommend to you.
Sometimes, these failures must have given you signs earlier on, before it degenerated to the “failed safe mode” it is/was now.
The experience below should be able to give some clues of what you should do, and expect.

Vehicle: Sienna 2005
Engine type: 3MZ-FE
Transmission type: Automatic
Mileage: over 240, 000miles(pls note its not kilometers).

1. transmission system upshift problem from gear 1 to the others.
After it gets to other gears, shifts is perfect.

1. Transmission fluid was recently replaced at a shop on the island; appeared reddish, which confirms fluid still has some life in it.
2. Checked and scanned the car for trouble codes, there was none.
3. Test drove the car, to simulate the customers complaints.
Initially, as you set off, the transmission system shifts properly; but when it gets heated up, shifts from gear #1 to other gears becomes problematic. After the transmission successfully shifts to the other gears, no problem was observed.

From the description of the way the transmission system is/was behaving, I concluded it was not a SOLENOID ACTUATOR(S), related problem, etc, because there was no trouble code that popped up on the dash.
If there was a potential electrical issue with the transmission system(short or open in any of the solenoid actuator’s circuitry, or a failed TCM), a check engine light would have being lit on the dashboard.
One or all of the solenoid actuators attached to a valve body maybe failing.
In some instances, if its hydraulically caused(inadequate transmission fluid supply, etc), there won’t be any codes showing on the dash, even with a scan, just like the case of this 2005 Siena some days ago.
Owner had replaced the transmission fluid with specified fluid(toyota T4), without any improvement from the shop.

1. Decided to removed the transmission system filter, and saw how totally clogged it was(hydraulically caused in this case. That was the reasons there wasn’t any related codes).
2. The filter upon removal, realised a portion of the filter was cracked. This was contributory to the drop in hydraulic pressure of the fluids to the actuators, and subsequently the valve body’s operations to actuate the bands/clutches to enable shifts.

That’s a vertical line crack at the middle of the transmission system filter there
This shows the actuators, and transmission valve body with its circuitry on display after removing the filter.

3. On assessing the two magnets in the transmission system pan cover, there was no metal chippings, or anything of that sort in there.
This tells me the problem of the transmission isn’t some sort of mechanical problem.
At least the bands/clutch, or internal gear teeth were intact.

Filter in the transmission system pan, showing the pan clean off metal chippings.
No signs of metal tear and wear yet.

4. Quality of the fluid, T4 in there was in good shape (reddish, and not burnt smelling stuff).
Conclusion: This confirms that the fluid was recently changed.
5. The mesh filter material in the plastic filter housing, was totally clogged(that tells me the shift solenoid actuators, especially the one responsible for shifts from #1 to others was experiencing insufficient hydraulic pressure supply, which was responsible for the upshifts problem.

That’s the filter mesh material displaying from the bigger opened hole there. See how clogesd it is. This would reduced system pressure absolutely!

6. I ordered a new filter for the transmission system, along side the pan gaskets.
7. Removed the old O seals on the old filter, and the gasket on the pan, and installed the new one.
I did lightly applied epoxy seal though on the gasket pan to prevent any leaks. Although, the sealant may not be necessary, since it was a new gasket for the pan.
8. Ensure no sealants get close anywhere the internals of the transmission system.

9. Test drove the car, and gracefully, the problem was rectified.
10. Please when you encounter transmission system issues like this, or any other, try checking and replacing your transmission fluid and FILTER.
The filters are to be replaced at a specified schedule.
It’s not to be used forever o!
Hope this would help anyone experiencing a transmission system apparent failure.
Don’t just conclude every transmission system problem means transmission replacement.
In some cases, outright transmission system replacement is the best approach, after all options have being considered.


The presence of moisture or water, is one of the causes of an ineffective brake application.

This occurs when the brake fluid is exposed to environmental air, which reacts with the chemistry of the fluid, thereby making brake application worthless.

Brake fluids just like any other fluids in a car’s system, essentially helps to cool critical components, prevents corrosion, and helps to transmit some forms of efforts where its required.


  1. Brake applications are always not effective in the sense that the brakes go all down to the floor, where you got to pump the brakes twice or thrice, to bring a car to a halt.
  2. The brakes has a spongy kind of feelings, when you apply the brakes.
  3. Opening the brake fluid reservoir, the colour of the brake fluids in there has a blackish colouration.
Shows a contaminated brake fluid as a result of oxidation
Brake fluid reservoir emptied of its contents. Notice the black colouration


  1. Could lead to safety concerns, especially an accident, if not properly addressed immediately.

This has led to several deaths, which could have being avoided in the first place.

2. Corrosion of vital brake system parts, such as caliper pistons, ABS module dysfunctions, corrosion of brake piping that leads to brake fluid leaks, and finally,

3. Brake fluids could spilled over to body paints, as a result of overfilled reservoir levels.

The more moisture in a brake fluid, the more the volumes of fluids in the reservoir.

An overfilled brake fluid reservoir


Since the operation of a braking system requires the system to be in a closed loop, it is pertinent to ensured that moisture is removed or reduced from getting access to the brake fluid.

  1. Use always the recommended brake fluid for your car. Some car manufacturers specify using DOT 3/DOT4 fluids only, and nothing else.
  2. Do not leave the brake fluid reservoir opened for a long time. Immediately close reservoir, after every openings.
  3. If the cover does not provide the necessary sealing of the reservoir, it is best to replaced it.
  4. Replace a failed brake salvo mechanism piston with an OEM one.
  5. Properly bleed the brake system of air, during brake jobs, and properly tightened bleeder valves using correct torque value.

A handheld vacuum pump used for bleeding the brakes on display
Salvo mechanism piston being compared side to side with another brake salvo master

Reservoir cap left open while filling the reservoir

Carrying out a brake systems flush, would go along way in curtailing some of these problems.

The salvo mechanism already removed

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