Spongy/Low Brake Pedal on '97 Previa

So I was driving my Previa tonight and I noticed that the brakes weren't being consistent in how much/hard I have to push down each time. Some stops the brake pedal would be firm and go halfway down (normal) and I would stop fine. Other times the brake pedal is really soft and I find myself putting my foot to the bottom of the floor in order to get the car to stop. The latter of the 2 really scares me when driving and wanted to know how to fix the problem. I was thinking that maybe the brake fluid level was low, but that would't result in inconsistent brake pedal, is would just be consistently at the bottom.

Any other suggestions to solve the problem?

It could be a few things, but it sounds like damage to your master cylinder. 1st thing to do is verify the reservoir is full. The next thing to do is look under the van to see if there are any leaks. Pay particular attention to areas around the wheels and the flexible brake hoses. If you don't have any experience with brakes, due to the obvious safety issues here, it might not be a bad idea take it into a shop for an estimate. Most shops won't charge you anything to tell you what's wrong. Depending on what they find and how much $$$, you may wish to just pay to have it done. Tim

Yeah I ended up doing some research on this after I saw your post and found youtube video on how to fix. The video told me to replace the master cylinder all together and then to bleed out the brakes. it all looked really easy to do and I think I might end up doing it myself.

next thing to do: find out master cylinder for the previa.

Thanks for the help Tim.

Hey Tim.

So I just checked the brake fluid and its full, So that means that there has to a leak somewhere in the system(prob not because the fluid is full) or there is air somewhere in the system.

So I'm gonna try to bleed the brakes.

It's possible that sometime in the past somebody opened the system and failed to properly bleed, so bleeding brakes is a good idea. I would certainly try this before replacing anything. If it is your master cylinder it is likely a damaged seal inside that allows fluid to leak between the pressurized and non-pressurized side. This wouldn't necessarily create an external leak. Tim

So I had an issue with my brakes and I posted a thread about it. Issue was that the brake pedal would have to be slammed to the floor just to get the car to slow down.

Looking into it some more I found some solutions. I tried bleeding my brakes and it didn't work. While only very little air came out it didn't fix the problem. I looked at the master cylinder and it looks brand new so my dad is automatically ruling it out.

The last step is to take it to the dealer and have them look at the hydraulic system. Does anyone know how much this could cost or how expensive it would be?

This new thread is pretty much a continuation of your old, so for organization reasons I merged them into 1. As previously stated the symptoms you describe sound like a damaged master cylinder. Exterior condition of this part should only be considered a clue (doesn't mean it's good or bad). Inside the master cylinder is a piston with seals / o-rings on it. When you step on the brakes the piston moves and forces fluid through the system. If it has a torn or otherwise damaged o-ring/seal it may not be capable of building/holding sufficient pressure. This may or may not be your problem, but I certainly wouldn't rule it out due to how it looks on the outside.

Most dealerships charge ~$100 per hr. There will be variables from one shop to another, but I would suspect about a 2 hr charge for this (troubleshooting, replacing master cylinder, & bleeding brakes). An aftermarket master cylinder can be had for around $50. Toyota's MSRP for a new master cylinder is around $280.00. Another possibility is just replacing the moving parts inside your existing cylinder. If you go this route, Toyota sells a kit for around $75. Note: this will increase the labor charge if you have it installed. In some cases the bore of the cylinder may be "pitted" and require honing. In some rare cases the pits are too deep and the cylinder must be replaced. For this reason (and potential liability issues) most shops won't mess around with repairing old cylinders. Tim

Hi Tim. So I took it to the dealer just to get it checked out and they said its the master cylinder (which is what I said and what my friend who's a mechanic said).

My dad didn't want to accept that it was the master cylinder because it looked "new" and was so set on it being something else. So Toyota is charging us $1000 to fix it as opposed to the $200 aftermarket one that I suggested multiple times. They said that the part is special order and will cost about $800. I have the ABS previa so that probably why its more expensive but yeah. Thanks for the help Tim!

Give me the VIN number and I'll get you the Toyota part number. I checked the EPC and see there are 3 or 4 master cylinders for that year. The most expensive one was $280 (and that was Toyota's MSRP). I also checked on www.rockauto.com and see they range from $50 - $165 for aftermarket. Tim

Sorry my mistake I goofed up there. Toyota is charging us $1000 to fix the car total. The car has other maintenance needs so thats why its costing so much. The cylinder is not $800, all the problems is has together is costing us $1000.