diff --git a/test/test_mortar_2d_contact.jl b/test/test_mortar_2d_contact.jl
index 114a6d0..fe28fd5 100644
--- a/test/test_mortar_2d_contact.jl
+++ b/test/test_mortar_2d_contact.jl
@@ -5,7 +5,29 @@ using JuliaFEM.Test
 
 using JuliaFEM.Core: Node, Seg2, Tri3, update!, calculate_normal_tangential_coordinates!,
                      PlaneStressLinearElasticityProblem, DirichletProblem, MortarProblem,
-                     get_elements, DirectSolver
+                     get_elements, DirectSolver, calculate_nodal_vector, FieldAssembly,
+                     FieldProblem, set_linear_system_solver!, set_nonlinear_max_iterations!
+
+import JuliaFEM.Core: postprocess_assembly!, linear_system_solver_preprocess!
+
+function postprocess_assembly!(assembly::FieldAssembly, problem::FieldProblem{PlaneStressLinearElasticityProblem}, time::Real)
+    f = full(assembly.force_vector)
+    info("force vector = $(f')")
+end
+
+function linear_system_solver_preprocess!(solver, iter, time, K, f, C1, C2, D, g, sol, la, ::Type{Val{:foo}})
+    info("stiffness matrix")
+    dump(round(full(K), 3))
+    info("constraint matrix C1")
+    dump(round(full(C1), 3))
+    info("constraint matrix C2")
+    dump(round(full(C2), 3))
+    info("force vector")
+    dump(round(full(f)', 3))
+    info("constraint vector")
+    dump(round(full(g)', 3))
+
+end
 
 macro debug(msg)
     haskey(ENV, "DEBUG") || return
@@ -14,24 +36,28 @@ end
 
 @testset "2d frictionless contact" begin
     nodes = Node[
-        [3.0, 3.0],
-        [4.0, 6.0],
+        [6.0, 6.0],
+        [7.0, 8.0],
         [0.0, 0.0],
-        [3.0, 0.0],
-        [4.0, 0.0],
-        [10.0, 0.0]]
-    fel1 = Tri3([3, 4, 1])
-    fel2 = Tri3([5, 6, 2])
+        [6.0, 0.0],
+        [7.0, 0.0],
+        [19.0, 0.0]]
+    fel1 = Tri3([1, 3, 4])
+    fel2 = Tri3([2, 5, 6])
+    force = Seg2([3, 1])
     bnd1 = Seg2([3, 4])
     bnd2 = Seg2([5, 6])
     sel = Seg2([1, 4])
     mel = Seg2([5, 2])
-    update!([fel1, fel2, sel, mel, bnd1, bnd2], "geometry", nodes)
+    update!([fel1, fel2, force, sel, mel, bnd1, bnd2], "geometry", nodes)
 
     prob = PlaneStressLinearElasticityProblem()
     push!(prob, fel1, fel2)
-    update!(get_elements(prob), "youngs modulus", 90.0)
-    update!(get_elements(prob), "poissons ratio", 0.25)
+    push!(prob, force)
+    update!([fel1, fel2], "youngs modulus", 90.0)
+    update!([fel1, fel2], "poissons ratio", 0.25)
+    update!([force], "displacement traction force 1", 6/sqrt(2))
+    fel1["displacement nodal load"] = Vector{Float64}[[0.0, 0.0], [0.0, 0.0], [18.0, 0.0]]
 
     bc = DirichletProblem("displacement", 2)
     push!(bc, bnd1, bnd2)
@@ -50,9 +76,20 @@ end
     solver = DirectSolver()
     push!(solver, prob)
     push!(solver, bc)
-    push!(solver, cont)
-    solver.method = :UMFPACK
-    solver.max_iterations = 5
-    call(solver, 0.0)
+#   push!(solver, cont)
+    set_linear_system_solver!(solver, :UMFPACK)
+    set_nonlinear_max_iterations!(solver, 2)
+    push!(solver.linear_system_solver_preprocessors, :foo)
+    time = 0.0
+    call(solver, time)
+
+    @debug begin
+        u = calculate_nodal_vector("displacement", 2, get_elements(prob), time)
+        info("solution vector")
+        dump(reshape(round(u, 8), 2, 6))
+        la = calculate_nodal_vector("reaction force", 2, get_elements(prob), time)
+        info("reaction force")
+        dump(reshape(round(la, 8), 2, 6))
+    end
 end