Brake pedal pushing hard and brakes not working as they should? (1 Viewer)

[landcruiserluke]

While waiting in a drive-thru going slow, my brake pedal will get hard to push and brakes not working as they should. Problem goes away.after a Couple of seconds. Does not happen all the time. Only at slow speeds. Looking for suggestions where to start.
If brake booster . Any suggestions on brand. Having brake job done I a week or so.

 

[ppc]

Bad booster, bad check valve or vacuum leak not necessarily at the booster. What is RPM's when this happens.

 

[Shipwreck]

Yes, double check vacuum, but you've described the classic intermittant hard pedal symptoms of a bad booster.

Seiken is the OEM manufacture of boosters:
New Toyota Land Cruiser LX450 OEM Seiken Brake Booster with Gaskets 44610-60792 - https://www.cruiseryard.com/80-series-new-oem-seiken-brake-booster-and-oem-gasket/

Damn, these things have gotten pricey since I replaced mine.

 

[Kernal]

Yeah, price has almost doubled in two years. Might save a bit from Amayama or Partsouq for the OEM part (44610-60792) but then there's shipping costs if going OEM.

Already mentioned (repeated): the Seiken booster is the exact same part as OEM and will save you a little cash. Don't waste your money on any other aftermarket booster, they're mostly junk rebuilds.

 

[BILT4ME]

I bought Toyota from partsouq.

I think @arcteryx is the guy with the Seiken deals.

 

[arcteryx]

Seiken is the OEM manufacture of boosters:
New Toyota Land Cruiser LX450 OEM Seiken Brake Booster with Gaskets 44610-60792 - https://www.cruiseryard.com/80-series-new-oem-seiken-brake-booster-and-oem-gasket/

Damn, these things have gotten pricey since I replaced mine.

Yes, and let me be the first to say I am NOT HAPPY with it either. Just a few years ago I sold them for $299.99. My margins have not changed, in fact a lot of my items have gotten slimmer. Price increase is everything that people are aware of- shipping, port fees, labor, inflation, etc.

I bought Toyota from partsouq.

I think @arcteryx is the guy with the Seiken deals.

Thanks, yes I have them in stock.

 

[White Stripe]

How many miles and years are on your current brake system components?

 

[Squash]

Suspect a sticky caliper puck.

 

[landcruiserluke]

I did find the vacuum hose was a little loose on the engine. Will test drive it today. Sounds like seiken booster is the way to go. Will search for best price.

 

[landcruiserluke]

Bad booster, bad check valve or vacuum leak not necessarily at the booster. What is RPM's when this happens.

This is happening at around 500 rpms. Only at idle. Not familiar with the check valve. Where is this located? I did find a loose hose but after tightening it's still happening. This is a random problem.

 

[landcruiserluke]

How many miles and years are on your current brake system components?

245 k miles, brake pads, rotors, and calipers changed on regular basis. Scheduled to brakes again in 2 weeks. Maybe I should hold off on booster. See what happens after brake job.

 

[White Stripe]

245 k miles, brake pads, rotors, and calipers changed on regular basis. Scheduled to brakes again in 2 weeks. Maybe I should hold off on booster. See what happens after brake job.

At 245k if thr booster, lspv, and master cylinder are original it's time to replace them in my opinion. You can het the upgraded booster that gives 30% more boost. I don't remember who sells it.

 

[Clemson TLC]

A few years ago I had a similar problem( 180K miles). Although the booster passed the FSM test, I replaced the booster ($298 in 2020, Seiken from Cruiser Yard) master cylinder, and brake hoses, but still had a problem.
Then replaced the LSPV and the ABS Module. I bought a used ABS and flushed it really good before I installed it. The ABS module has a tenancy to trap old brake fluid in the internal reservoirs that doesn't get flushed in is typical brake system flush.
I think the LSVP was bad because I had overlooked it in a previous brake fluid flush. If not flushed, the moisture creates corrosion so it doesn't seal well.

Brakes are really good now. I'm thinking it was probably the LSVP.

Good luck.

 

[Kernal]

@landcruiserluke "brakes not working as they should"

Guess we should have asked earlier; what exactly do you feel (what's happening) when you press on the brake pedal besides it's harder to push: less braking effect overall, pulling to one side or the other, grabbing and letting go/stuttering effect, any new noises while braking, reservoir full, any recent brake work, ----?

If it's the booster going bad it will get worse with time; make sure your emergency brake works well just in case you need it.

 

[SpenserAK]

This is happening at around 500 rpms. Only at idle. Not familiar with the check valve. Where is this located? I did find a loose hose but after tightening it's still happening. This is a random problem.

That's low for 1fz idle, though I wouldn't worry too much. Should be 650 +/- 50 when hot, IIRC. Some other things to look into at the same time.

 

[ppc]

Low RPM means less vacuum generated and longer recovery time of vacuum into the booster. First press of the brake peddle may be okay but gets worse if pumping the pedal. If the booster is marginally leaking then this can greater impact.

 

[Kernal]

@landcruiserluke: Check the major vacuum hoses (PCV and Breather) that run to the top of the valve cover, leaks in those can lead to low idle rpms IME (you already checked the brake booster vacuum line?). If those vacuum hoses are hard as a rock and/or have any cracks it's a good idea to replace them. Also check the larger air intake tube for cracks between the pleats.

 

[landcruiserluke]

A few years ago I had a similar problem( 180K miles). Although the booster passed the FSM test, I replaced the booster ($298 in 2020, Seiken from Cruiser Yard) master cylinder, and brake hoses, but still had a problem.
Then replaced the LSPV and the ABS Module. I bought a used ABS and flushed it really good before I installed it. The ABS module has a tenancy to trap old brake fluid in the internal reservoirs that doesn't get flushed in is typical brake system flush.
I think the LSVP was bad because I had overlooked it in a previous brake fluid flush. If not flushed, the moisture creates corrosion so it doesn't seal well.

Brakes are really good now. I'm thinking it was probably the LSVP.

Good luck.

Interesting, never thought of lspv.

 

[another]

One other thing, if you're working alone, set the booster in place, get some wood blocking and shore it up against the battery compartment while you install the firewall nuts. A couple of feet of 1by2 and some cut pieces for shims will hold it well.

 

[another]

One other thing, if you're working alone, set the booster in place, get some wood blocking and shore it up against the battery compartment while you install the firewall nuts. A couple of feet of 1by2 and some cut pieces for shims will hold it well.

Also, I used a 4 foot long aluminum folding platform, like you would use for painting/etc indoor low ceiling work, but you can make one out of a piece of scrap plywood or 1x12 lumber and some 2x4, extend it out from the running boards and put some blankets or foam down. Makes a nice bench that you can lay on and get your head/arms/hands up in the space and work comfortably. Only problem is getting up after being down there for awhile.