Extreme Terrain
4x4Wire Trail Talk Forums: Jeep, Toyota, Mitsubishi, Pajero, Isuzu, Kia, 4WD, 4x4, SUV, Off-Road and OutdoorWire Forums


Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
brake pedal extremely hard #953796 07/14/09 11:59 PM
Joined: Jun 2007
Posts: 16
C
celticta2s Offline OP
Need a Spot
As I was driving to lunch today. I went to stop at a light, and the pedal started normal and then got really hard. The pedal needs to be pressed extremely hard to get the truck to stop. I changed out my rotors about a month ago, but have not had problems until today. Could it need to be bleed? It's almost like the booster went out or ...?

I am still at work and I don't think I want to drive it the 30 miles home on the highway.

Any help would be much appreciated!


1994 X-Cab V6 Auto 4X4 (3VZ-E/A340H)
Re: brake pedal extremely hard [Re: celticta2s] #953797 07/15/09 12:08 AM
Joined: Sep 2003
Posts: 1,686
Staceman Offline
Body Damage is Cool
Make sure there is no air leak with the hose between the brake booste and intake manifold. Start there I'd guess. Possible that the diaphram blew out in the booster. Unlikely, but not impossible.


85 4Runner - With NEW Marlin 4.7 Gears!! It's a whole new beast!
Re: brake pedal extremely hard [Re: Staceman] #953798 07/15/09 12:21 AM
Joined: Jun 2007
Posts: 16
C
celticta2s Offline OP
Need a Spot
The hose is fine. It was the third or fourth time I had to stop that this happened. Any other suggestions on what to check?


1994 X-Cab V6 Auto 4X4 (3VZ-E/A340H)
Re: brake pedal extremely hard [Re: celticta2s] #953799 07/15/09 12:51 AM
Joined: Apr 2002
Posts: 3,568
Snowtoy Offline
Roll Me Over
Bleeding isn't likely the problem. Air in the lines would tend to give you a soft pedal, or one that fades. A failing Master cylinder would tend to do the same

I know when stalling on a hill climb off road, the brake pedal in both rigs is stiff, so my first guess would be you are not getting assistance from the brake booster. Check the vacuum lines, one may have come loose, is collapsing, or cracked, then check to see if the vacuum pressure from the engine is, and whether or not the brake booster has a leak.


More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed
Re: brake pedal extremely hard [Re: Snowtoy] #953800 07/15/09 04:24 PM
Joined: Jun 2007
Posts: 16
C
celticta2s Offline OP
Need a Spot
I reluctantly drove it home last night...

Anyways, I checked the vacuum lines, and all appeared to be fine. They were still pliable, with good connections. I pulled the line off at the booster with the engine running, and there was, what seemed to be, plenty of suction.

How go you check for a booster leak on these. There are no visual signs of a fluid leak, and I don't hear a air (vacuum) leak.


1994 X-Cab V6 Auto 4X4 (3VZ-E/A340H)
Re: brake pedal extremely hard [Re: celticta2s] #953801 07/15/09 04:29 PM
Joined: May 2009
Posts: 177
Ralph Offline
Wheeler
Is there missing brake fluid
Look for signs of brake fluid inside the booster, or the vacume line to it.


Ralph

1991 Toyota 4x4 Standard Cab Pickup.
engnbldr cam and head.
Doug Thorley Headers
Home Made Cat Backs
30x9.5x15 BF Goodrich All-Terrain M/T KM2
Re: brake pedal extremely hard [Re: Ralph] #953802 07/15/09 04:49 PM
Joined: Jun 2007
Posts: 16
C
celticta2s Offline OP
Need a Spot
The brake fluid is unchanged. The level is right at the Max Level line, and I don't see any leaking at any of the fittings.


1994 X-Cab V6 Auto 4X4 (3VZ-E/A340H)
Re: brake pedal extremely hard [Re: celticta2s] #953803 07/15/09 04:55 PM
Joined: Jan 2001
Posts: 11,595
Adam F Offline
Forum Moderator
A hard pedal means the booster is not doing its job.

Check the one way valve on the booster (the plastic piece in between the line and the booster) You should be able to blow in it one way but not the other.

Testing your booster with a vacuum gauge

http://www.type2.com/library/brakes/vacboo.htm


88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride
Re: brake pedal extremely hard [Re: Adam F] #953804 07/15/09 05:13 PM
Joined: Jun 2007
Posts: 16
C
celticta2s Offline OP
Need a Spot
Thanks for the link.

I will give it a try tonight when I get home.


1994 X-Cab V6 Auto 4X4 (3VZ-E/A340H)
Re: brake pedal extremely hard [Re: celticta2s] #953805 07/15/09 05:32 PM
Joined: Oct 2006
Posts: 121
suba Offline
Wheeler
Have you recently added any fluid to the system?


86 4runner, pro comp AAL, Kayline Soft top, 31's but all stock
Page 1 of 2 1 2

Moderated by  4Crawler, 4x4Wire, kewlynx 







4x4Wire Social:

| 4x4Wire on FaceBook |


OutdoorWire, 4x4Wire, JeepWire, TrailTalk, MUIRNet-News, and 4x4Voice are all trademarks and publications of OutdoorWire, Inc. and MUIRNet Consulting.
Copyright (c) 1999-2019 OutdoorWire, Inc and MUIRNet Consulting - All Rights Reserved, no part of this publication may be reproduced in any form without express written permission
You may link freely to this site, but no further use is allowed without the express written permission of the owner of this material.
All corporate trademarks are the property of their respective owners.

Powered by UBB.threads™ PHP Forum Software 7.7.3
(Release build 20190728)
PHP: 7.4.33 Page Time: 0.007s Queries: 16 (0.005s) Memory: 0.6357 MB (Peak: 0.7589 MB) Data Comp: Off Server Time: 2026-06-07 09:49:35 UTC
Valid HTML 5 and Valid CSS