Contaminated, sluggish or seized up guide elements
Floating calliper guide pins - practical repair tips
Here you will find useful basic information and valuable tips all about guide bolts on a floating-type calliper.
The floating-type calliper, also known as a floating calliper, is one of the most frequently used brake callipers in vehicles. A special feature here is that the brake calliper can be moved by means of guide bolts. This type of mounting is also referred to as floating mounting. When the brake is applied, the brake piston presses against the inner brake pad and presses this against the brake disc. The reaction force moves the brake calliper onto the guide bolt and pushes the outer brake pad against the brake disc with the same force.
Important safety note
The following technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for suitably qualified personnel only.
TABLE OF CONTENTS
Contaminated, sluggish or seized up guide elements: Effects
In order for everything to function perfectly, both freedom and also ease of movement must be guaranteed.
Depending on the type of brake calliper, the guide bolts in the brake calliper carrier can be guided internally and sealed with dust protection sleeves or screwed onto the outside and mounted continuously in damping sleeves.
Contaminated, sluggish or seized up guide elements lead to a limited functioning of the brake calliper and can have the following effects:
- Increased wear of brake pads/linings and brake discs
- Uneven lining wear
- Inadequate or one-sided braking behaviour
- Increased heating up of material / thermal overload
- Brake discs discoloured on one side or subject to shrinkage/wearing
- Increased noise when the brake is not applied
- Severe, one-sided wheel dirt caused by brake abrasion
In some cases, the wear pattern of the old removed brake linings may already indicate a possible cause.
Guide bolts with damping sleeves
Checking and servicing floating-type brake calliper guide bolts: Video
Practical repair instructions - guide pins on brake calliper (floating-type)
In this video we show you repair and maintenance of the guide bolts on a floating-type calliper.
Practical repair instructions - floating brake calliper guide pins: Instructions
Checking guide bolt and dust protection sleeve
Figure 1: It should be possible to easily move the guide bolts back and forth in the brake calliper carrier.
Figure 2: Various repair kits are on offer depending on the vehicle model and brake calliper type.
The following must be observed during all repair or maintenance work on the floating-type calliper:
- Check guide bolts for ease of movement, contamination or damage
- Check dust protection sleeves or damping sleeves for damage.
- It should be possible to easily move the guide bolts back and forth in the brake calliper carrier (Figure 1).
- Contaminated components should be cleaned before re-use and replaced if necessary
However, damaged components must always be replaced.
Depending on the vehicle model and brake calliper type, various repair kits are on offer (Figure 2).
Apply a thin layer of a suitable lubricant to the sliding surfaces
Figure 3: Sliding surfaces are thinly coated with a suitable silicone-based lubricant
Figure 4: Damaged rubber bush as a result of material expansion and shearing
Before inserting the internal guide bolts, the sliding surfaces are to be coated thinly with a suitable silicone-based lubricant (Figure 3).
Unsuitable lubricants can lead to swelling of the rubber parts and subsequent faults on the wheel brake (Figure 4).
Before the brake is reassembled, the brake piston and the dust protection sleeve should also be checked for correct functioning and for any damage and replaced if necessary. Improper maintenance or repair work can lead to unpleasant complaints or cost-intensive consequential damage.
Important!
The brake system is a safety system. Repair work on the brake calliper should only be carried out by qualified specialist personnel.
In connection with this information, please also always observe the maintenance and repair instructions of each individual vehicle manufacturer!
Schematic representations, figures and descriptions serve only the purpose of explanation and presentation of the document texts and cannot be used as a basis for carrying out the repair.