Astra G rear caliper identification (1998-2004)

Like if this guide is helpful

This guide contains the information required to help you identify which make and size of caliper you have fitted to your Astra G.

Astra G models have either Bosch or Lucas calipers fitted on the rear, they also use 3 piston sizes in each caliper type.
  1. Firstly idendify which caliper make you have fitted, either Bosch or Lucas
  2. Secondly you will need to identify the piston diameter, either 34mm, 36mm or 38mm
To identify your caliper correctly please read this information carefully and if unsure, give us a call.
Bosch style rear caliper
Link to an eBay page Remove
Add up to 3 more photos
Link to an eBay page
Bosch style rear caliper

Bosch calipers

  • Usually fitted from 1998-2001
  • Visible cooling fins in the casting
  • Top guide pin is screwed into the caliper casting
  • Sizes are 34mm, 36mm and 38mm
  • Piston size commonly in the area marked with a red circle
Lucas style rear caliper
Link to an eBay page Remove
Add up to 3 more photos
Link to an eBay page
Lucas style rear caliper

Lucas Calipers

  • Usually fitted from 2001-2004
  • No visible cooling fins in the casting
  • Both guide pins separate from the caliper casting
  • Sizes are 34mm, 36mm and 38mm
  • Piston size commonly in the area marked with a red circle

Use these links to take you to the correct repair kit for your caliper

Clicking on the size will link to the correct listing for that size of caliper repair kit.
Bosch have 3 caliper sizes:-
Bosch caliper - 34mm piston diameter
Bosch caliper - 36mm piston diameter
Bosch caliper - 38mm piston diameter

If your vehicle has Lucas calipers fitted, see the links below
Lucas also have 3 caliper sizes:-
Lucas caliper - 34mm piston diameter
Lucas caliper -  36mm piston diameter
Lucas caliper - 38mm piston diameter

So, firstly identify what make of caliper you have, Bosch or Lucas then identify the piston size. The images above should help with this but please be aware, caliper manufacturers don't always put the piston size in the same place.
If you decide to measure the piston please ensure your measure the piston body and not just the top as this is often smaller.
When assembling rubber brake parts it is important to use the correct grease, we recommend using only Red Rubber Grease or other suitable products designed specifically for the purpose.
Finally, if you are unsure, please give us a call and will will try to help.
Frentech-uk

Have something to share? Create your own guide... Write a guide
Explore more guides